Conformations of three heterocyclic perhydro­pyrrolobenzofurans and polymeric assembly via co-operative inter­molecular C—H⋯O hydrogen bonds

Yathirajan, H.S.; Narasegowda, R.S.; Lynch, D.E.; Narasimhamurthy, T.; Rathore, R.S.

doi:10.1107/S010827010601119X

organic compounds

STRUCTURAL
CHEMISTRY

ISSN: 2053-2296

Volume 62| Part 5| May 2006| Pages o277-o280

doi:10.1107/S010827010601119X

Conformations of three heterocyclic perhydropyrrolobenzofurans and polymeric assembly via co-operative intermolecular C—H⋯O hydrogen bonds

H. S. Yathirajan,^a R. S. Narasegowda,^a D. E. Lynch,^b T. Narasimhamurthy ^c and R. S. Rathore ^d ^*

^aDepartment of Studies in Chemistry, University of Mysore, Mysore 570 006, India, ^bFaculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, England, ^cD210, Indian Institute of Science, Bangalore 560 012, India, and ^dOriental Organization of Molecular and Structural Biology, 203 Agarwal Bhavan, Malleshwaram, Bangalore 560 055, India
^*Correspondence e-mail: ravindranath_rathore@yahoo.com

(Received 23 March 2006; accepted 28 March 2006; online 13 April 2006)

In 1-cyclohexyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, C₁₉H₂₇NO₃, (I), and the isomorphous compounds 6,6,8a-trimethyl-1-phenyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, C₁₉H₂₁NO₃, (II), and 6,6,8a-trimethyl-1-(3-pyridyl)-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, C₁₈H₂₀N₂O₃, (III), the tetrahydrobenzo–dihydrofuro–pyrrolidine ring systems are folded at the cis junction of the five-membered rings, giving rise to a non-planar shape of the tricyclic cores. The dihydrofuran and pyrrolidine rings in (I) are puckered and adopt an envelope conformation. The cyclohexene rings adopt a half-chair conformation in all the molecules, while the substituent N-cyclohexyl ring in (I) assumes a chair form. Short intramolecular C—H⋯O contacts form S(5) and S(6) motifs. The isomorphous compounds (II) and (III) are effectively isostructural, and aggregate into chains via intermolecular C—H⋯O hydrogen bonds.

Comment

Co-operativity is an important property of intermolecular interactions and, thereby, molecules assemble into polymers with distinct patterns of interactions. By the process of mutual polarization within a polymeric assembly, weaker interactions acquire greater strength than they otherwise possess. A dimer of two molecules intermolecularly connected by symmetrical hydrogen bonds is more stable than if they are connected by an isolated hydrogen bond, the stability of a tetramer is greater than that of a pair of dimers, and so on (Desiraju & Steiner, 1999 ; Sharma & Desiraju, 1994 ). Polymeric assemblies formed by co-operative weak interactions are the subject of the present discussion. In this report, we present examples of a new class of tricyclic benzofuran derivatives with a benzofuropyrrolidine ring skeleton. The structural and conformational analyses of three compounds have been undertaken, namely 1-cyclohexyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, (I), 1-phenyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, (II), and 1-pyridin-3-yl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, (III). These chiral molecules are formally derived from a perhydrofuro(or -pyrrolo)benzofuran system, and they have previously been shown to exhibit hypoglycaemic activity (Nagarajan et al., 1988 ).

The stereogenic centres C3a and C8a in compounds (I)–(III) (Figs. 1–3 ) adopt RS and SR configurations, respectively (Cahn et al., 1966 ). The core of each molecule consists of fused tetrahydrobenzo (A), dihydrofuro (B) and pyrrolidine (C) rings. The C3b=C7a double bond at the AB ring junction is in the range 1.341 (2)–1.344 (2) Å. In each compound, the B and C rings are folded at the BC ring junction, which is cis-fused (Bucourt, 1974 ). The angles between the best planes through ring B (atoms O8/C8a/C3a/C3b/C7a) and ring C (atoms N1/C2/C3/C3a/C8a) are 66.4 (1), 63.8 (1) and 63.2 (1)°, respectively, while the crossed torsion angles at the junction, i.e. N1—C8a—C3a—C3b and O8—C8a—C3a—C3, are 103.2 (1) and −130.2 (1), 114.3 (1) and −121.2 (1), and 113.4 (1) and −122.3 (1)°, respectively, in the molecules of (I)–(III).

The folding at the BC ring junction gives rise to the non-planarity of the tricyclic ring system. The structures of two analogous molecules based on a chiral tricyclic tetrahydrobenzo–dihydrofuro–tetrahydrofuran (or pyrrolidine) core, namely 1-isopropyl-6,6,8a-trimethyl-1,3a,5,6,7,8a-hexahydro-3H-1-benzofuro[2,3-b]pyrrole-2,4-dione (Narasegowda et al., 2006 ), (IV), and 6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-benzo[b]furo[3,2-d]furan-2,4(3H,5H)-dione (Nagaraj et al., 2005 ), (V), also possess a similar non-planar shape of the tricyclic core, and the equivalent crossed torsion angles at the junctions of the five-membered rings are 99.7 (1) and −132.8 (1) (values correspond to an inverted image of the reported structure), and 104.0 (1) and −127.2 (1)°, respectively.

The superposition of all five available structures of perhydrofuro(or -pyrrolo)benzofuran derivatives is shown in supplementary Fig. 5. The conformations of the substituent rings, i.e. N-cyclohexyl in (I), N-phenyl in (II) and N-pyridyl in (III), are described by torsion angles C8a—N1—C12—C13 of −112.4 (1), −117.2 (2) and −120.2 (1)°, respectively.

The isomorphous compounds (II) and (III), with a difference of one atom [C14 in (II) and N14 in (III)] are isostructural. The degree of isostructurality has been quantitatively described by two descriptors, i.e. the unit-cell similarity index, Π, which is the difference between orthogonalized lattice parameters, and the isostructurality index, I_i(n), where n is the number of distance differences between identical non-H atoms (Kálmán et al., 1993 ). The calculated values of Π = 0.019 and I_i(24) = 99.7% indicate the structures are close to the ideal case of isostructrality.

The internal torsion angles of the heterocyclic rings are listed in Figs. 1–3 . Ring A (cyclohexene) adopts a half-chair (C₂) conformation in all three molecules. However, its conformation, i.e. a half-chair (C₂) versus a sofa (C_s), is hardly distinguishable in the present structures (Bucourt, 1974). The N-cyclohexyl ring in (I) assumes a chair form, with the larger tricyclic system in the equatorial position. The puckering (Cremer & Pople, 1975 ) and asymmetric (Duax et al., 1976 ) parameters of individual rings are provided in supplementary Table 4. The five-membered B and C rings in (I) are puckered and adopt envelope (C_s) conformations (Fuchs, 1978 ), with atoms C8a and C3a at the flaps of the envelopes. Atoms C8a and C3a are 0.18 (1) and 0.27 (1) Å, respectively, out of the best planes formed by the other four atoms of the ring. Rings B and C are planar in (II) and (III). The least-squares planes formed by atoms of rings A and B (C3a/C3b/C4/C5/C7/C7a/O8/C8a) and ring C (N1/C2/O2/C3/C3a/C8a) intercept at an angle of 65.8 (1)° in (II) and 64.2 (1)° in (III).

The parameters for intramolecular short contacts and intermolecular hydrogen bonds are given in Tables 1–3 . The conserved intramolecular C—H⋯O short contacts in (I)–(III) were observed between the donors of the N-substituents and atom O8 of ring B (Figs. 1–3 ). The short contact C12—H12⋯O8 forms an S(5) motif (Bernstein et al., 1995 ) in (I), while S(6) motifs are formed by C17—H17⋯O8 in (II) and (III). Additionally, an intramolecular C17—H171⋯O2 contact forms an S(6) motif in (I). The crystal packing in (I) is entirely due to van der Waals interactions. The crystal structures of isostructural compounds (II) and (III) are held together primarily by intermolecular C—H⋯O hydrogen bonds (Tables 2 and 3), forming chains of rings along [100] (Fig. 4). The significance of the co-operativity of weak intermolecular interactions for molecular self-assembly is elucidated in the present examples.

Figure 1
The molecular structure of (I)

, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Numerical data refer to the internal torsion angles (°) of the individual rings (s.u. values vary between 0.1 and 0.3°). Intramolecular C—H⋯O short contacts are shown as dashed lines.

Figure 2
The molecular structure of (II)

, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Numerical data refer to the internal torsion angles (°) of the individual rings (s.u. values vary between 0.1 and 0.3°). The intramolecular C—H⋯O short contact is shown as a dashed line.

Figure 3
The molecular structure of (III)

Figure 4
The crystal packing, showing the co-operative C—H⋯O hydrogen-bonded polymeric association of isostructural compounds (II)

and (III)

, viewed along the a axis. The representative diagram corresponds to the packing in (II)

. Atoms labelled with an asterisk (*) or a hash (#) are at the symmetry positions (−x + 1, −y + 1, −z + 1) and (x + 1, y, z), respectively. Intermolecular C—H⋯O hydrogen bonds are shown as dashed lines.

Experimental

The synthetic procedures used for the preparation of compounds (I)–(III) are as described in the literature (Nagarajan et al., 1988). Single crystals suitable for X-ray diffraction were grown by slow evaporation of solutions containing the following solvents (in a 1:1 ratio): for (I), ethanol and water; for (II), dichloromethane and hexane; for (III), benzene and hexane.

Compound (I)

Crystal data

C₁₉H₂₇NO₃
M_r = 317.42
Triclinic, $[P \overline 1]$
a = 9.4708 (2) Å
b = 10.2139 (2) Å
c = 10.7512 (2) Å
α = 105.804 (1)°
β = 99.141 (1)°
γ = 116.320 (1)°
V = 848.50 (3) Å³
Z = 2
D_x = 1.242 Mg m⁻³
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 120 (2) K
Plate, colourless
0.24 × 0.16 × 0.03 mm

Data collection

Nonius KappaCCD area-detector diffractometer
φ and ω scans
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ) T_min = 0.891, T_max = 0.998
18064 measured reflections
3327 independent reflections
2990 reflections with I > 2σ(I)
R_int = 0.039
θ_max = 26.0°

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.039
wR(F²) = 0.107
S = 1.12
3327 reflections
316 parameters
All H-atom parameters refined
w = 1/[σ²(F_o²) + (0.0495P)² + 0.3127P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max = 0.001
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Table 1
Hydrogen-bond and short-contact geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯O8	1.00 (2)	2.52 (2)	2.920 (2)	103 (1)
C17—H171⋯O2	1.01 (2)	2.55 (2)	3.153 (2)	118 (1)

Compound (II)

Crystal data

C₁₉H₂₁NO₃
M_r = 311.37
Triclinic, $[P \overline 1]$
a = 7.2348 (2) Å
b = 10.1212 (5) Å
c = 11.6287 (6) Å
α = 77.031 (2)°
β = 79.285 (3)°
γ = 76.872 (3)°
V = 799.89 (6) Å³
Z = 2
D_x = 1.293 Mg m⁻³
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 120 (2) K
Plate, colourless
0.20 × 0.14 × 0.03 mm

Data collection

Nonius KappaCCD area-detector diffractometer
φ and ω scans
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) T_min = 0.903, T_max = 0.997
14845 measured reflections
3132 independent reflections
2562 reflections with I > 2σ(I)
R_int = 0.047
θ_max = 26.0°

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.117
S = 1.07
3132 reflections
292 parameters
All H-atom parameters refined
w = 1/[σ²(F_o²) + (0.0532P)² + 0.358P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max = 0.001
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Table 2
Hydrogen-bond and short-contact geometry (Å, °) for (II)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C17—H17⋯O8	1.00 (2)	2.49 (2)	3.066 (2)	116 (2)
C7—H72⋯O2ⁱ	0.96 (2)	2.49 (2)	3.275 (2)	140 (2)
C16—H16⋯O2ⁱⁱ	0.98 (2)	2.46 (2)	3.243 (3)	138 (2)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x+1, y, z.

Compound (III)

Crystal data

C₁₈H₂₀N₂O₃
M_r = 312.36
Triclinic, $[P \overline 1]$
a = 7.2330 (2) Å
b = 9.8165 (3) Å
c = 11.6008 (3) Å
α = 78.541 (2)°
β = 78.992 (2)°
γ = 77.302 (1)°
V = 778.13 (4) Å³
Z = 2
D_x = 1.333 Mg m⁻³
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 120 (2) K
Prism, colourless
0.19 × 0.14 × 0.09 mm

Data collection

Nonius KappaCCD area-detector diffractometer
φ and ω scans
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) T_min = 0.913, T_max = 0.992
13914 measured reflections
3040 independent reflections
2769 reflections with I > 2σ(I)
R_int = 0.035
θ_max = 26.0°

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.039
wR(F²) = 0.104
S = 1.07
3040 reflections
288 parameters
All H-atom parameters refined
w = 1/[σ²(F_o²) + (0.0478P)² + 0.3717P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max = 0.006
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Table 3
Hydrogen-bond and short-contact geometry (Å, °) for (III)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C17—H17⋯O8	0.99 (2)	2.50 (2)	3.060 (2)	116 (2)
C7—H72⋯O2ⁱ	0.99 (2)	2.49 (2)	3.295 (2)	138 (1)
C16—H16⋯O2ⁱⁱ	0.97 (2)	2.54 (2)	3.268 (2)	132 (2)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x+1, y, z.

Larger-than-expected values of residual electron density were observed in (I) and (III) [the values of Δρ_max and Δρ_min were 0.75 and −0.88 e Å⁻³, respectively, in (I), and 0.82 and −0.87 e Å⁻³, respectively, in (III)]. This was attributed to the presence of a few poorly fitting low-angle reflections [(011), ( $[\overline{1}]$ $[\overline{1}]$ 1), (020), (111) and ( $[\overline{2}]$ $[\overline{1}]$ 2) in (I), and (1 $[\overline{1}]$ 2), (100), ( $[\overline{1}]$ 11), (022), (013), (122) and (012) in (III)], which appeared to have been truncated by the beam stop. These reflections were omitted during the final cycles of refinement. The residual electron density was then featureless and the residual factor R dropped from 0.053 to 0.039 in (I), and from 0.056 to 0.039 in (III) for observed data.

H atoms were located in difference maps and were refined freely. Refined methine, methylene and methyl C—H distances are as follows: for (I), 0.99 (2), 0.97 (2)–1.01 (2) and 0.96 (2)–1.02 (2) Å; for (II), 0.97 (2), 0.96 (2)–1.01 (2) and 0.97 (2)–1.03 (2) Å, with aromatic C—H = 0.96 (2)–1.00 (2) Å; for (III), 0.99 (2), 0.97 (2)–1.02 (2) and 0.98 (2)–1.02 (2) Å, with aromatic C—H = 0.97 (2)–1.01 (2) Å.

For all compounds, data collection: COLLECT (Nonius, 1998 ); cell refinement: DENZO (Otwinowski & Minor, 1997 ) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997 ), PLATON (Spek, 2003 ) and INSIGHTII (Accelrys, 2002 ); software used to prepare material for publication: SHELXL97 and PLATON.

Supporting information

Crystal structure: contains datablocks global, I, II, III. DOI: 10.1107/S010827010601119X/gd3014sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S010827010601119X/gd3014Isup2.hkl

Structure factors: contains datablock II. DOI: 10.1107/S010827010601119X/gd3014IIsup3.hkl

Structure factors: contains datablock III. DOI: 10.1107/S010827010601119X/gd3014IIIsup4.hkl

Supporting information file. DOI: 10.1107/S010827010601119X/gd3014sup5.pdf

Supporting information file. DOI: 10.1107/S010827010601119X/gd3014sup6.pdf

Comment top

Co-operativity is an important property of intermolecular interactions, and thereby molecules assemble into polymers with distinct patterns of interactions. By the process of mutual polarization within a polymeric assembly, weaker interactions acquire greater strength than they otherwise possess. A dimer of two molecules intermolecularly connected by symmetrical hydrogen bonds is more stable than if they are connected by an isolated hydrogen bond, the stability of a tetramer is greater than that of a pair of dimers, and so on (Desiraju & Steiner, 1999; Sharma & Desiraju, 1994). Polymeric assemblies formed by cooperative weak interactions are the subject of the present discussion. In this report, we present examples of a new class of tricyclic benzofuran derivatives with a benzofuropyrrolidine ring skeleton. The structural and conformational analyses of three compounds have been undertaken: 1-cyclohexyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-[1]benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, (I), 1-phenyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-[1]benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, (II), and 1-pyridin-3-yl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-[1]benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, (III). These chiral molecules are formally derived from a perhydrofuro(or -pyrrolo)benzofuran system, and they have previously been shown to exhibit hypoglycaemic activity (Nagarajan et al., 1988).

The stereogenic centres C3a and C8a in compounds (I)–(III) (Figs. 1–3) adopt RS and SR configurations, respectively (Cahn et al., 1966). The core of each molecule consists of fused tetrahydrobenzo (A), dihydrofuro (B) and pyrrolidine (C) rings. The C3b═C7a double bond at the AB ring junction is in the range 1.341 (2)–1.344 (2) Å. In each compound, the B and C rings are folded at the BC ring junction, which is cis-fused (Bucourt, 1974). The angles between the best planes through ring B (atoms O8/C8a/C3a/C3b/C7a) and ring C (atoms N1/C2/C3/C3a/C8a) are 66.4 (1), 63.8 (1) and 63.2 (1)°, respectively, while the crossed torsion angles at the junction, i.e. N1—C8a—C3a—C3b and O8—C8a—C3a—C3, are 103.2 (1) and −130.2 (1)°, 114.3 (1) and −121.2 (1)°, and 113.4 (1) and −122.3 (1)°, respectively, in the molecules of (I)–(III).

The folding at the BC ring junction gives rise to the non-planarity of the tricyclic ring system. The structures of two analogous molecules based on a chiral tricyclic tetrahydrobenzo–dihydrofuro–tetrahydrofuran(or pyrrolidine) core, namely 1-isopropyl-6,6,8a-trimethyl-1,3a,5,6,7,8a-hexahydro-3H-1-benzofuro[2,3-b]pyrrole-2,4-dione (Narasegowda et al., 2006), (IV), and 6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-benzo[b]furo[3,2-d]furan-2,4(3H,5H)-dione (Nagaraj et al., 2005), (V), also possess a similar non-planar shape of the tricyclic core, and the equivalent crossed torsion angles at the junctions of the five-membered rings are 99.7 (1) and −132.8 (1)° (values correspond to an inverted image of the reported structure) and 104.0 (1) and −127.2 (1)°, respectively.

The superposition of all five available structures of perhydrofuro- (or -pyrrolo)benzofuran derivatives is shown in supplementary Fig. 5. The conformations of the substituent rings, i.e. N-cyclohexyl in (I), N-phenyl in (II) and N-pyridyl in (III), are described by torsion angles C8a—N1—C12—C13 = −112.4 (1), −117.2 (2) and −120.2 (1)°, respectively.

The isomorphous compounds (II) and (III), with a difference of one atom [C14 in (II)/N14 in (III)] are isostructural. The degree of isostructurality has been quantitatively described by two descriptors, i.e. the unit-cell similarity index, Π, which is the difference between orthogonalized lattice parameters, and the isostructurality index, I_i(n), where n is the number of distance differences between identical non-H atoms (Kálmán et al., 1993). The calculated values of Π = 0.019 and I_i(24) = 99.7% indicate the structures are close to the ideal case of isostructrality.

The internal torsion angles of the heterocyclic rings are listed in Figs. 1–3. Ring A (cyclohexene) adopts a half-chair (C₂) conformation in all three molecules. However, its conformation, i.e. a half-chair (C₂) versus a sofa (C_s), is hardly distinguishable in the present structures (Bucourt, 1974). The N-cyclohexyl ring in (I) assumes a chair form, with the larger tricyclic system in the equatorial position. The puckering (Cremer & Pople, 1975) and asymmetric (Duax et al., 1976) parameters of individual rings are provided in supplementary Table 4. The five-membered B and C rings in (I) are puckered and adopt envelope (C_s) conformations (Fuchs, 1978), with atoms C8a and C3a at the flaps of the envelopes. Atoms C8a and C3a are 0.18 (1) and 0.27 (1) Å, respectively, out of the best planes formed by the other four atoms of the ring. Rings B and C are planar in (II) and (III). The least square planes formed by atoms of rings A and B (C3a/C3b/C4/C5/C7/C7a/O8/C8a) and ring C (N1/C2/O2/C3/C3a/C8a) intercept at an angle of 65.8 (1)° in (II) and 64.2 (1)° in (III).

The parameters for intramolecular short contacts and intermolecular hydrogen bonds are given in Tables 1–3. The conserved intramolecular C—H···O short contacts in (I)–(III) were observed between the donors of the N-substituents and atom O8 of ring B (Figs. 1–3). The short contact C12—H12···O8 forms an S(5) motif (Bernstein et al., 1995) in (I), while S(6) motifs are formed by C17—H17···O8 in (II) and (III). Additionally, an intramolecular C17—H171···O2 contact forms an S(6) motif in (I). The crystal packing in (I) is entirely due to van der Waals interactions. The crystal structures of isostructural compounds (II) and (III) are held together primarily by intermolecular C—H···O hydrogen bonds (Tables 2 and 3), forming chains of rings along [100] (Fig. 4). The significance of the cooperativity of weak intermolecular interactions for molecular self-assembly is elucidated in the present examples.

Experimental top

The synthetic procedures for compounds (I)–(III) are as described in the literature (Nagarajan et al., 1988). Suitable single crystals for X-ray diffraction were grown by slow evaporation of solutions containing the following solvents (in 1:1 ratio): for (I), ethyl alcohol and water; for (II), dichloromethane and hexane; for (III), benzene and hexane.

Computing details top

For all compounds, data collection: COLLECT (Nonius, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Farrugia, 1997), PLATON (Spek, 2003) and INSIGHTII (Accelrys, 2002); software used to prepare material for publication: SHELXL97 and PLATON).

Figures top

Fig. 1. The molecular structure of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Numerical data refer to the internal torsion angles (°) of the individual rings (s.u.s vary between 0.1 and 0.3°). Intramolecular C—H···O short contacts are shown as dashed lines.

Fig. 2. The molecular structure of (II), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Numerical data refer to the internal torsion angles (°) of the individual rings (s.u.s vary between 0.1 and 0.3°). The intramolecular C—H···O short contact is shown as a dashed line.

Fig. 3. The molecular structure of (III), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Numerical data refer to the internal torsion angles (°) of the individual rings (s.u.s vary between 0.1 and 0.3°). The intramolecular C—H···O short contact is shown as a dashed line.

Fig. 4. The crystal packing, showing the cooperative C—H···O hydrogen-bonded polymeric association of the isostructural compounds (II) and (III), viewed along the a axis. The representative diagram corresponds to the packing in (II). Atoms labelled with an asterisk (*) or a hash (#) are at the symmetry positions (−x + 1, −y + 1, −z + 1) and (x + 1, y, z), respectively. Intermolecular C—H···O hydrogen bonds are shown as dashed lines.

Fig. 5. (Supplementary material). A superposition diagram of all five structures of the tricyclic compounds (I)–(V), which are derived from a perhydrofuro (or -pyrrolo)benzofuran system. The r.m.s. deviations are in the range 0.05–0.26 Å, with respect to (II). Colour scheme: (I) blue, (II) green, (III) cyan, (IV) magenta and (V) orange.

(I) 1-cyclohexyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro- 1H-[1]benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione top

Crystal data top

C₁₉H₂₇NO₃	Z = 2
M_r = 317.42	F(000) = 344
Triclinic, P1	D_x = 1.242 Mg m⁻³
Hall symbol: -P 1	Melting point: 164(1) K
a = 9.4708 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.2139 (2) Å	Cell parameters from 3830 reflections
c = 10.7512 (2) Å	θ = 2.9–27.5°
α = 105.804 (1)°	µ = 0.08 mm⁻¹
β = 99.141 (1)°	T = 120 K
γ = 116.320 (1)°	Plate, colourless
V = 848.50 (3) Å³	0.24 × 0.16 × 0.03 mm

Data collection top

Nonius KappaCCD area-detector diffractometer	3327 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode	2990 reflections with I > 2σ(I)
10 cm confocal mirrors monochromator	R_int = 0.039
Detector resolution: 9.091 pixels mm^-1	θ_max = 26.0°, θ_min = 3.1°
ϕ and ω scans	h = −11→11
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −12→12
T_min = 0.891, T_max = 0.998	l = −13→13
18064 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.039	Hydrogen site location: difference Fourier map
wR(F²) = 0.107	All H-atom parameters refined
S = 1.12	w = 1/[σ²(F_o²) + (0.0495P)² + 0.3127P] where P = (F_o² + 2F_c²)/3
3327 reflections	(Δ/σ)_max = 0.001
316 parameters	Δρ_max = 0.30 e Å⁻³
0 restraints	Δρ_min = −0.32 e Å⁻³

Crystal data top

C₁₉H₂₇NO₃	γ = 116.320 (1)°
M_r = 317.42	V = 848.50 (3) Å³
Triclinic, P1	Z = 2
a = 9.4708 (2) Å	Mo Kα radiation
b = 10.2139 (2) Å	µ = 0.08 mm⁻¹
c = 10.7512 (2) Å	T = 120 K
α = 105.804 (1)°	0.24 × 0.16 × 0.03 mm
β = 99.141 (1)°

Data collection top

Nonius KappaCCD area-detector diffractometer	3327 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	2990 reflections with I > 2σ(I)
T_min = 0.891, T_max = 0.998	R_int = 0.039
18064 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	0 restraints
wR(F²) = 0.107	All H-atom parameters refined
S = 1.12	Δρ_max = 0.30 e Å⁻³
3327 reflections	Δρ_min = −0.32 e Å⁻³
316 parameters

Special details top

Experimental. The minimum and maximum absorption values stated above are those calculated in SHELXL97 from the given crystal dimensions. The ratio of minimum to maximum apparent transmission was determined experimentally as 0.872591.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.66945 (13)	0.83321 (13)	0.06540 (11)	0.0167 (2)
C2	0.54206 (16)	0.76998 (16)	0.11506 (14)	0.0195 (3)
O2	0.39388 (12)	0.69213 (12)	0.04877 (10)	0.0268 (2)
C3	0.61545 (17)	0.81694 (17)	0.26714 (14)	0.0205 (3)
H31	0.566 (2)	0.723 (2)	0.2919 (17)	0.028 (4)*
H32	0.586 (2)	0.892 (2)	0.3135 (16)	0.025 (4)*
C3a	0.80351 (16)	0.89310 (15)	0.29567 (13)	0.0177 (3)
H3A	0.8681 (19)	0.9908 (18)	0.3799 (16)	0.019 (4)*
C3b	0.86820 (15)	0.78212 (15)	0.29228 (13)	0.0175 (3)
C4	0.86882 (15)	0.69968 (16)	0.38229 (13)	0.0195 (3)
O4	0.82106 (12)	0.71866 (12)	0.48206 (10)	0.0260 (2)
C5	0.93232 (17)	0.58661 (17)	0.34377 (15)	0.0232 (3)
H51	0.836 (2)	0.483 (2)	0.2755 (19)	0.035 (5)*
H52	0.965 (2)	0.564 (2)	0.4265 (18)	0.029 (4)*
C6	1.07746 (16)	0.64508 (16)	0.28581 (14)	0.0202 (3)
C7	1.02171 (17)	0.67990 (16)	0.16153 (14)	0.0198 (3)
H71	1.119 (2)	0.7370 (19)	0.1328 (16)	0.024 (4)*
H72	0.939 (2)	0.580 (2)	0.0830 (18)	0.030 (4)*
C7a	0.94005 (15)	0.77378 (15)	0.19475 (13)	0.0167 (3)
O8	0.93695 (11)	0.86367 (11)	0.12332 (9)	0.0180 (2)
C8a	0.83307 (15)	0.92847 (15)	0.16778 (13)	0.0167 (3)
C9	1.1212 (2)	0.51662 (18)	0.23972 (17)	0.0287 (3)
H91	1.212 (2)	0.550 (2)	0.1979 (18)	0.034 (5)*
H92	1.022 (2)	0.418 (2)	0.1693 (18)	0.033 (4)*
H93	1.161 (2)	0.492 (2)	0.320 (2)	0.040 (5)*
C10	1.22956 (17)	0.79503 (18)	0.39645 (15)	0.0244 (3)
H101	1.261 (2)	0.776 (2)	0.4802 (19)	0.038 (5)*
H102	1.211 (2)	0.889 (2)	0.4228 (18)	0.033 (4)*
H103	1.328 (2)	0.828 (2)	0.3632 (18)	0.037 (5)*
C11	0.92108 (18)	1.10020 (16)	0.18603 (15)	0.0219 (3)
H111	0.939 (2)	1.112 (2)	0.1012 (19)	0.032 (4)*
H112	1.028 (2)	1.158 (2)	0.2568 (18)	0.030 (4)*
H113	0.851 (2)	1.142 (2)	0.2104 (18)	0.034 (5)*
C12	0.65163 (16)	0.81188 (15)	−0.07822 (13)	0.0170 (3)
H12	0.7669 (19)	0.8633 (17)	−0.0830 (15)	0.016 (3)*
C13	0.56535 (18)	0.89201 (17)	−0.12881 (14)	0.0216 (3)
H131	0.449 (2)	0.8404 (19)	−0.1287 (16)	0.024 (4)*
H132	0.622 (2)	1.005 (2)	−0.0663 (17)	0.027 (4)*
C14	0.56686 (18)	0.87682 (16)	−0.27380 (14)	0.0231 (3)
H141	0.685 (2)	0.935 (2)	−0.2711 (17)	0.027 (4)*
H142	0.512 (2)	0.931 (2)	−0.3057 (17)	0.029 (4)*
C15	0.48386 (18)	0.70394 (16)	−0.37073 (14)	0.0217 (3)
H151	0.362 (2)	0.648 (2)	−0.3810 (17)	0.027 (4)*
H152	0.491 (2)	0.6975 (19)	−0.4646 (17)	0.024 (4)*
C16	0.56366 (18)	0.62014 (16)	−0.31776 (13)	0.0209 (3)
H161	0.679 (2)	0.6661 (19)	−0.3198 (16)	0.025 (4)*
H162	0.503 (2)	0.507 (2)	−0.3774 (18)	0.029 (4)*
C17	0.56744 (17)	0.63732 (15)	−0.17124 (13)	0.0192 (3)
H171	0.451 (2)	0.5785 (19)	−0.1672 (16)	0.024 (4)*
H172	0.629 (2)	0.5888 (19)	−0.1361 (17)	0.025 (4)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0141 (5)	0.0185 (5)	0.0162 (5)	0.0077 (4)	0.0039 (4)	0.0066 (4)
C2	0.0184 (7)	0.0206 (6)	0.0231 (7)	0.0117 (6)	0.0083 (5)	0.0093 (5)
O2	0.0157 (5)	0.0338 (6)	0.0274 (5)	0.0099 (4)	0.0063 (4)	0.0124 (4)
C3	0.0202 (7)	0.0259 (7)	0.0212 (7)	0.0148 (6)	0.0098 (5)	0.0105 (6)
C3a	0.0181 (6)	0.0190 (6)	0.0161 (6)	0.0099 (5)	0.0057 (5)	0.0061 (5)
C3b	0.0151 (6)	0.0201 (6)	0.0162 (6)	0.0090 (5)	0.0037 (5)	0.0063 (5)
C4	0.0125 (6)	0.0234 (7)	0.0185 (6)	0.0059 (5)	0.0031 (5)	0.0092 (5)
O4	0.0245 (5)	0.0353 (6)	0.0200 (5)	0.0138 (5)	0.0100 (4)	0.0143 (4)
C5	0.0201 (7)	0.0259 (7)	0.0287 (7)	0.0118 (6)	0.0087 (6)	0.0170 (6)
C6	0.0182 (7)	0.0225 (7)	0.0243 (7)	0.0118 (6)	0.0073 (5)	0.0124 (6)
C7	0.0195 (7)	0.0230 (7)	0.0210 (7)	0.0129 (6)	0.0084 (5)	0.0097 (6)
C7a	0.0142 (6)	0.0176 (6)	0.0160 (6)	0.0069 (5)	0.0024 (5)	0.0071 (5)
O8	0.0182 (5)	0.0236 (5)	0.0189 (4)	0.0137 (4)	0.0082 (4)	0.0111 (4)
C8a	0.0148 (6)	0.0188 (6)	0.0171 (6)	0.0097 (5)	0.0051 (5)	0.0060 (5)
C9	0.0310 (8)	0.0279 (8)	0.0387 (9)	0.0204 (7)	0.0147 (7)	0.0177 (7)
C10	0.0176 (7)	0.0286 (8)	0.0275 (7)	0.0121 (6)	0.0045 (6)	0.0128 (6)
C11	0.0199 (7)	0.0186 (7)	0.0235 (7)	0.0081 (6)	0.0045 (6)	0.0076 (6)
C12	0.0158 (6)	0.0189 (6)	0.0163 (6)	0.0088 (5)	0.0049 (5)	0.0069 (5)
C13	0.0256 (7)	0.0210 (7)	0.0216 (7)	0.0150 (6)	0.0068 (6)	0.0079 (6)
C14	0.0269 (8)	0.0226 (7)	0.0229 (7)	0.0145 (6)	0.0061 (6)	0.0111 (6)
C15	0.0218 (7)	0.0238 (7)	0.0184 (7)	0.0110 (6)	0.0050 (5)	0.0084 (5)
C16	0.0227 (7)	0.0197 (7)	0.0188 (6)	0.0113 (6)	0.0060 (5)	0.0052 (5)
C17	0.0208 (7)	0.0182 (6)	0.0191 (6)	0.0109 (6)	0.0050 (5)	0.0072 (5)

Geometric parameters (Å, º) top

N1—C2	1.3635 (17)	C9—H91	1.006 (19)
N1—C8a	1.4482 (16)	C9—H92	0.994 (19)
N1—C12	1.4702 (16)	C9—H93	1.02 (2)
C2—O2	1.2222 (17)	C10—H101	0.999 (19)
C2—C3	1.5175 (19)	C10—H102	1.022 (18)
C3—C3a	1.5295 (18)	C10—H103	1.003 (19)
C3—H31	0.994 (18)	C11—H111	0.982 (18)
C3—H32	0.971 (17)	C11—H112	0.965 (18)
C3a—C3b	1.5040 (17)	C11—H113	0.968 (19)
C3a—C8a	1.5500 (17)	C12—C13	1.5256 (18)
C3a—H3A	0.990 (16)	C12—C17	1.5263 (18)
C3b—C7a	1.3414 (18)	C12—H12	0.998 (15)
C3b—C4	1.4463 (18)	C13—C14	1.5270 (19)
C4—O4	1.2294 (16)	C13—H131	0.990 (17)
C4—C5	1.5171 (19)	C13—H132	0.991 (17)
C5—C6	1.5432 (18)	C14—C15	1.5260 (19)
C5—H51	0.997 (19)	C14—H141	0.998 (18)
C5—H52	1.013 (17)	C14—H142	0.998 (18)
C6—C9	1.5267 (19)	C15—C16	1.5266 (19)
C6—C10	1.5305 (19)	C15—H151	1.002 (17)
C6—C7	1.5465 (18)	C15—H152	1.009 (17)
C7—C7a	1.4845 (18)	C16—C17	1.5296 (18)
C7—H71	0.995 (17)	C16—H161	0.983 (17)
C7—H72	0.991 (18)	C16—H162	0.982 (18)
C7a—O8	1.3544 (15)	C17—H171	1.011 (17)
O8—C8a	1.4795 (15)	C17—H172	1.010 (17)
C8a—C11	1.5080 (18)

C2—N1—C8a	114.36 (10)	C6—C9—H92	109.9 (10)
C2—N1—C12	125.58 (11)	H91—C9—H92	107.6 (14)
C8a—N1—C12	120.06 (10)	C6—C9—H93	111.2 (10)
O2—C2—N1	125.67 (12)	H91—C9—H93	107.9 (15)
O2—C2—C3	125.93 (12)	H92—C9—H93	109.1 (15)
N1—C2—C3	108.38 (11)	C6—C10—H101	111.0 (11)
C2—C3—C3a	105.27 (10)	C6—C10—H102	112.4 (10)
C2—C3—H31	110.5 (10)	H101—C10—H102	108.9 (14)
C3a—C3—H31	113.6 (10)	C6—C10—H103	110.3 (10)
C2—C3—H32	106.7 (10)	H101—C10—H103	107.0 (15)
C3a—C3—H32	112.0 (10)	H102—C10—H103	107.1 (14)
H31—C3—H32	108.6 (14)	C8a—C11—H111	111.6 (10)
C3b—C3a—C3	114.80 (11)	C8a—C11—H112	109.7 (10)
C3b—C3a—C8a	100.65 (10)	H111—C11—H112	108.8 (14)
C3—C3a—C8a	104.98 (10)	C8a—C11—H113	107.6 (11)
C3b—C3a—H3A	111.6 (9)	H111—C11—H113	108.2 (15)
C3—C3a—H3A	112.6 (9)	H112—C11—H113	110.8 (15)
C8a—C3a—H3A	111.3 (9)	N1—C12—C13	113.06 (10)
C7a—C3b—C4	121.24 (12)	N1—C12—C17	111.57 (10)
C7a—C3b—C3a	110.25 (11)	C13—C12—C17	111.68 (11)
C4—C3b—C3a	128.39 (11)	N1—C12—H12	106.2 (8)
O4—C4—C3b	122.91 (12)	C13—C12—H12	107.8 (8)
O4—C4—C5	122.29 (12)	C17—C12—H12	106.0 (8)
C3b—C4—C5	114.80 (11)	C12—C13—C14	109.33 (11)
C4—C5—C6	114.23 (11)	C12—C13—H131	109.5 (10)
C4—C5—H51	107.3 (11)	C14—C13—H131	109.5 (9)
C6—C5—H51	110.1 (10)	C12—C13—H132	110.1 (10)
C4—C5—H52	108.7 (10)	C14—C13—H132	110.9 (10)
C6—C5—H52	110.6 (9)	H131—C13—H132	107.4 (13)
H51—C5—H52	105.4 (14)	C15—C14—C13	111.61 (11)
C9—C6—C10	109.47 (11)	C15—C14—H141	109.3 (10)
C9—C6—C5	109.62 (11)	C13—C14—H141	108.5 (10)
C10—C6—C5	109.49 (11)	C15—C14—H142	111.6 (10)
C9—C6—C7	109.26 (11)	C13—C14—H142	108.9 (10)
C10—C6—C7	110.43 (11)	H141—C14—H142	106.9 (14)
C5—C6—C7	108.56 (11)	C14—C15—C16	111.25 (11)
C7a—C7—C6	110.36 (11)	C14—C15—H151	109.5 (9)
C7a—C7—H71	110.5 (9)	C16—C15—H151	109.4 (10)
C6—C7—H71	110.5 (9)	C14—C15—H152	110.0 (9)
C7a—C7—H72	107.3 (10)	C16—C15—H152	110.1 (9)
C6—C7—H72	110.3 (10)	H151—C15—H152	106.6 (13)
H71—C7—H72	107.9 (13)	C15—C16—C17	112.04 (11)
C3b—C7a—O8	114.43 (11)	C15—C16—H161	109.1 (10)
C3b—C7a—C7	126.56 (12)	C17—C16—H161	108.6 (10)
O8—C7a—C7	119.00 (11)	C15—C16—H162	110.2 (10)
C7a—O8—C8a	106.82 (9)	C17—C16—H162	109.3 (10)
N1—C8a—O8	107.81 (9)	H161—C16—H162	107.5 (14)
N1—C8a—C11	113.69 (11)	C12—C17—C16	110.26 (11)
O8—C8a—C11	107.18 (10)	C12—C17—H171	109.3 (9)
N1—C8a—C3a	104.22 (10)	C16—C17—H171	110.9 (9)
O8—C8a—C3a	106.56 (10)	C12—C17—H172	109.5 (9)
C11—C8a—C3a	116.88 (11)	C16—C17—H172	110.3 (9)
C6—C9—H91	111.0 (10)	H171—C17—H172	106.4 (13)

C8a—N1—C2—O2	176.43 (13)	C3b—C7a—O8—C8a	−6.95 (14)
C12—N1—C2—O2	−3.5 (2)	C7—C7a—O8—C8a	173.97 (11)
C8a—N1—C2—C3	−1.88 (14)	C2—N1—C8a—O8	124.67 (11)
C12—N1—C2—C3	178.23 (11)	C12—N1—C8a—O8	−55.44 (14)
O2—C2—C3—C3a	172.73 (13)	C2—N1—C8a—C11	−116.66 (12)
N1—C2—C3—C3a	−8.97 (14)	C12—N1—C8a—C11	63.23 (15)
C2—C3—C3a—C3b	−94.13 (13)	C2—N1—C8a—C3a	11.71 (14)
C2—C3—C3a—C8a	15.40 (13)	C12—N1—C8a—C3a	−168.40 (10)
C3—C3a—C3b—C7a	119.17 (12)	C7a—O8—C8a—N1	−100.30 (11)
C8a—C3a—C3b—C7a	7.05 (13)	C7a—O8—C8a—C11	136.94 (11)
C3—C3a—C3b—C4	−64.82 (17)	C7a—O8—C8a—C3a	11.09 (12)
C8a—C3a—C3b—C4	−176.94 (12)	C3b—C3a—C8a—N1	103.18 (11)
C7a—C3b—C4—O4	171.61 (13)	C3—C3a—C8a—N1	−16.30 (13)
C3a—C3b—C4—O4	−4.0 (2)	C3b—C3a—C8a—O8	−10.68 (12)
C7a—C3b—C4—C5	−8.72 (18)	C3—C3a—C8a—O8	−130.16 (10)
C3a—C3b—C4—C5	175.66 (12)	C3b—C3a—C8a—C11	−130.43 (11)
O4—C4—C5—C6	−143.62 (13)	C3—C3a—C8a—C11	110.10 (13)
C3b—C4—C5—C6	36.71 (16)	C2—N1—C12—C13	67.52 (16)
C4—C5—C6—C9	−175.28 (12)	C8a—N1—C12—C13	−112.36 (13)
C4—C5—C6—C10	64.61 (15)	C2—N1—C12—C17	−59.36 (16)
C4—C5—C6—C7	−56.01 (15)	C8a—N1—C12—C17	120.76 (12)
C9—C6—C7—C7a	166.22 (11)	N1—C12—C13—C14	174.79 (11)
C10—C6—C7—C7a	−73.33 (14)	C17—C12—C13—C14	−58.39 (15)
C5—C6—C7—C7a	46.71 (15)	C12—C13—C14—C15	57.18 (15)
C4—C3b—C7a—O8	−176.75 (11)	C13—C14—C15—C16	−55.25 (16)
C3a—C3b—C7a—O8	−0.41 (16)	C14—C15—C16—C17	53.56 (16)
C4—C3b—C7a—C7	2.3 (2)	N1—C12—C17—C16	−175.37 (10)
C3a—C3b—C7a—C7	178.59 (12)	C13—C12—C17—C16	57.00 (14)
C6—C7—C7a—C3b	−22.69 (18)	C15—C16—C17—C12	−54.13 (15)
C6—C7—C7a—O8	156.26 (11)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···O8	1.00 (2)	2.52 (2)	2.920 (2)	103 (1)
C17—H171···O2	1.01 (2)	2.55 (2)	3.153 (2)	118 (1)

(II) 6,6,8a-trimethyl-1-phenyl-3a,6,7,8a-tetrahydro- 1H-[1]benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione top

Crystal data top

C₁₉H₂₁NO₃	Z = 2
M_r = 311.37	F(000) = 332
Triclinic, P1	D_x = 1.293 Mg m⁻³
Hall symbol: -P 1	Melting point: 140(2) K
a = 7.2348 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.1212 (5) Å	Cell parameters from 3590 reflections
c = 11.6287 (6) Å	θ = 2.9–27.5°
α = 77.031 (2)°	µ = 0.09 mm⁻¹
β = 79.285 (3)°	T = 120 K
γ = 76.872 (3)°	Plate, colourless
V = 799.89 (6) Å³	0.20 × 0.14 × 0.03 mm

Data collection top

Nonius KappaCCD area-detector diffractometer	3132 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode	2562 reflections with I > 2σ(I)
10 cm confocal mirrors monochromator	R_int = 0.047
Detector resolution: 9.091 pixels mm^-1	θ_max = 26.0°, θ_min = 2.9°
ϕ and ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −12→12
T_min = 0.903, T_max = 0.997	l = −14→14
14845 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.044	Hydrogen site location: difference Fourier map
wR(F²) = 0.117	All H-atom parameters refined
S = 1.07	w = 1/[σ²(F_o²) + (0.0532P)² + 0.358P] where P = (F_o² + 2F_c²)/3
3132 reflections	(Δ/σ)_max = 0.001
292 parameters	Δρ_max = 0.19 e Å⁻³
0 restraints	Δρ_min = −0.27 e Å⁻³

Crystal data top

C₁₉H₂₁NO₃	γ = 76.872 (3)°
M_r = 311.37	V = 799.89 (6) Å³
Triclinic, P1	Z = 2
a = 7.2348 (2) Å	Mo Kα radiation
b = 10.1212 (5) Å	µ = 0.09 mm⁻¹
c = 11.6287 (6) Å	T = 120 K
α = 77.031 (2)°	0.20 × 0.14 × 0.03 mm
β = 79.285 (3)°

Data collection top

Nonius KappaCCD area-detector diffractometer	3132 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	2562 reflections with I > 2σ(I)
T_min = 0.903, T_max = 0.997	R_int = 0.047
14845 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.117	All H-atom parameters refined
S = 1.07	Δρ_max = 0.19 e Å⁻³
3132 reflections	Δρ_min = −0.27 e Å⁻³
292 parameters

Special details top

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.53606 (19)	0.30937 (14)	0.42290 (12)	0.0209 (3)
C2	0.3437 (2)	0.36441 (17)	0.43875 (15)	0.0223 (4)
O2	0.24353 (17)	0.36463 (13)	0.53525 (11)	0.0296 (3)
C3	0.2786 (2)	0.41965 (19)	0.31800 (15)	0.0248 (4)
H31	0.206 (3)	0.518 (2)	0.3145 (18)	0.033 (5)*
H32	0.186 (3)	0.363 (2)	0.3108 (18)	0.035 (5)*
C3a	0.4618 (2)	0.40507 (17)	0.22711 (15)	0.0213 (4)
H3A	0.450 (2)	0.3570 (18)	0.1666 (16)	0.019 (4)*
C3b	0.5317 (2)	0.53744 (17)	0.17369 (14)	0.0202 (4)
C4	0.4436 (2)	0.65604 (17)	0.09400 (14)	0.0214 (4)
O4	0.29576 (16)	0.65975 (13)	0.05405 (11)	0.0287 (3)
C5	0.5429 (2)	0.77911 (17)	0.06436 (16)	0.0231 (4)
H51	0.480 (3)	0.836 (2)	0.1238 (19)	0.033 (5)*
H52	0.510 (3)	0.837 (2)	−0.0145 (19)	0.031 (5)*
C6	0.7623 (2)	0.74438 (16)	0.06188 (14)	0.0202 (4)
C7	0.8135 (2)	0.64350 (17)	0.17734 (15)	0.0213 (4)
H71	0.953 (3)	0.6045 (19)	0.1685 (17)	0.027 (5)*
H72	0.790 (3)	0.690 (2)	0.2432 (19)	0.030 (5)*
C7a	0.7005 (2)	0.53281 (16)	0.20819 (13)	0.0194 (3)
O8	0.76859 (15)	0.41247 (11)	0.27893 (10)	0.0212 (3)
C8a	0.6254 (2)	0.32326 (17)	0.29942 (14)	0.0207 (4)
C9	0.8360 (3)	0.87696 (18)	0.05386 (17)	0.0268 (4)
H91	0.978 (3)	0.858 (2)	0.0516 (17)	0.030 (5)*
H92	0.780 (3)	0.924 (2)	0.125 (2)	0.041 (6)*
H93	0.807 (3)	0.946 (2)	−0.023 (2)	0.041 (6)*
C10	0.8578 (2)	0.67838 (18)	−0.04603 (15)	0.0223 (4)
H101	0.829 (3)	0.746 (2)	−0.1224 (18)	0.028 (5)*
H102	0.811 (3)	0.590 (2)	−0.0433 (17)	0.030 (5)*
H103	0.996 (3)	0.6566 (19)	−0.0463 (16)	0.024 (5)*
C11	0.7320 (3)	0.18778 (19)	0.26597 (17)	0.0274 (4)
H111	0.843 (3)	0.149 (2)	0.3114 (19)	0.035 (5)*
H112	0.784 (3)	0.201 (2)	0.179 (2)	0.036 (5)*
H113	0.644 (3)	0.122 (2)	0.2840 (19)	0.037 (6)*
C12	0.6379 (2)	0.23257 (17)	0.51912 (14)	0.0215 (4)
C13	0.5764 (3)	0.11657 (18)	0.59018 (16)	0.0273 (4)
H13	0.461 (3)	0.090 (2)	0.5753 (18)	0.031 (5)*
C14	0.6768 (3)	0.03986 (19)	0.68169 (16)	0.0301 (4)
H14	0.636 (3)	−0.041 (2)	0.7312 (19)	0.034 (5)*
C15	0.8373 (3)	0.07839 (19)	0.70262 (16)	0.0282 (4)
H15	0.909 (3)	0.026 (2)	0.766 (2)	0.038 (6)*
C16	0.8983 (3)	0.1942 (2)	0.63108 (16)	0.0288 (4)
H16	1.009 (3)	0.224 (2)	0.6464 (18)	0.036 (5)*
C17	0.7987 (2)	0.27232 (19)	0.53922 (15)	0.0256 (4)
H17	0.842 (3)	0.356 (2)	0.4875 (18)	0.032 (5)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0215 (7)	0.0238 (7)	0.0163 (7)	−0.0059 (5)	−0.0020 (5)	−0.0002 (6)
C2	0.0230 (9)	0.0234 (8)	0.0204 (9)	−0.0085 (7)	−0.0013 (7)	−0.0014 (7)
O2	0.0272 (7)	0.0374 (7)	0.0205 (6)	−0.0062 (5)	0.0012 (5)	−0.0015 (5)
C3	0.0217 (9)	0.0323 (10)	0.0203 (9)	−0.0093 (7)	−0.0039 (7)	0.0001 (7)
C3a	0.0236 (9)	0.0258 (8)	0.0165 (8)	−0.0096 (7)	−0.0038 (6)	−0.0027 (7)
C3b	0.0207 (8)	0.0246 (8)	0.0161 (8)	−0.0078 (6)	−0.0009 (6)	−0.0033 (7)
C4	0.0197 (8)	0.0269 (9)	0.0159 (8)	−0.0037 (7)	−0.0002 (6)	−0.0034 (7)
O4	0.0221 (6)	0.0369 (7)	0.0263 (7)	−0.0066 (5)	−0.0076 (5)	0.0000 (5)
C5	0.0223 (9)	0.0213 (8)	0.0229 (9)	−0.0018 (7)	−0.0023 (7)	−0.0015 (7)
C6	0.0195 (8)	0.0213 (8)	0.0188 (8)	−0.0046 (6)	−0.0029 (6)	−0.0009 (7)
C7	0.0224 (9)	0.0244 (8)	0.0181 (8)	−0.0071 (7)	−0.0042 (6)	−0.0023 (7)
C7a	0.0224 (8)	0.0215 (8)	0.0125 (7)	−0.0044 (6)	−0.0006 (6)	−0.0009 (6)
O8	0.0209 (6)	0.0225 (6)	0.0195 (6)	−0.0077 (5)	−0.0047 (4)	0.0022 (5)
C8a	0.0217 (8)	0.0236 (8)	0.0169 (8)	−0.0100 (6)	0.0001 (6)	−0.0011 (7)
C9	0.0294 (10)	0.0227 (9)	0.0290 (10)	−0.0087 (7)	−0.0055 (8)	−0.0012 (8)
C10	0.0216 (9)	0.0263 (9)	0.0178 (9)	−0.0060 (7)	−0.0027 (6)	−0.0002 (7)
C11	0.0299 (10)	0.0257 (9)	0.0257 (10)	−0.0065 (8)	0.0003 (8)	−0.0051 (7)
C12	0.0236 (9)	0.0230 (8)	0.0164 (8)	−0.0031 (6)	−0.0021 (6)	−0.0026 (7)
C13	0.0318 (10)	0.0264 (9)	0.0253 (9)	−0.0107 (7)	−0.0056 (7)	−0.0015 (7)
C14	0.0369 (10)	0.0249 (9)	0.0251 (9)	−0.0072 (8)	−0.0038 (8)	0.0032 (8)
C15	0.0276 (9)	0.0320 (10)	0.0198 (9)	0.0024 (7)	−0.0042 (7)	−0.0020 (7)
C16	0.0256 (9)	0.0370 (10)	0.0243 (9)	−0.0090 (8)	−0.0050 (7)	−0.0026 (8)
C17	0.0271 (9)	0.0279 (9)	0.0217 (9)	−0.0088 (7)	−0.0031 (7)	−0.0008 (7)

Geometric parameters (Å, º) top

N1—C2	1.371 (2)	C7a—O8	1.3531 (19)
N1—C12	1.434 (2)	O8—C8a	1.4768 (19)
N1—C8a	1.451 (2)	C8a—C11	1.508 (2)
C2—O2	1.217 (2)	C9—H91	1.00 (2)
C2—C3	1.510 (2)	C9—H92	1.02 (2)
C3—C3a	1.535 (2)	C9—H93	1.03 (2)
C3—H31	1.01 (2)	C10—H101	1.02 (2)
C3—H32	1.00 (2)	C10—H102	1.02 (2)
C3a—C3b	1.501 (2)	C10—H103	0.970 (19)
C3a—C8a	1.552 (2)	C11—H111	1.00 (2)
C3a—H3A	0.966 (18)	C11—H112	1.00 (2)
C3b—C7a	1.343 (2)	C11—H113	0.99 (2)
C3b—C4	1.442 (2)	C12—C13	1.387 (2)
C4—O4	1.233 (2)	C12—C17	1.387 (2)
C4—C5	1.519 (2)	C13—C14	1.387 (3)
C5—C6	1.542 (2)	C13—H13	0.99 (2)
C5—H51	0.98 (2)	C14—C15	1.383 (3)
C5—H52	1.01 (2)	C14—H14	0.96 (2)
C6—C10	1.531 (2)	C15—C16	1.387 (3)
C6—C9	1.531 (2)	C15—H15	0.97 (2)
C6—C7	1.543 (2)	C16—C17	1.390 (3)
C7—C7a	1.476 (2)	C16—H16	0.97 (2)
C7—H71	0.99 (2)	C17—H17	1.00 (2)
C7—H72	0.96 (2)

C2—N1—C12	122.99 (13)	O8—C7a—C7	118.76 (14)
C2—N1—C8a	114.62 (13)	C7a—O8—C8a	107.56 (12)
C12—N1—C8a	122.13 (13)	N1—C8a—O8	109.09 (12)
O2—C2—N1	124.65 (15)	N1—C8a—C11	113.28 (14)
O2—C2—C3	126.54 (15)	O8—C8a—C11	106.32 (13)
N1—C2—C3	108.79 (14)	N1—C8a—C3a	104.50 (12)
C2—C3—C3a	105.57 (13)	O8—C8a—C3a	106.50 (12)
C2—C3—H31	109.6 (12)	C11—C8a—C3a	116.83 (14)
C3a—C3—H31	113.8 (12)	C6—C9—H91	111.3 (11)
C2—C3—H32	106.9 (12)	C6—C9—H92	112.9 (12)
C3a—C3—H32	113.5 (12)	H91—C9—H92	106.1 (16)
H31—C3—H32	107.3 (16)	C6—C9—H93	111.2 (12)
C3b—C3a—C3	114.78 (14)	H91—C9—H93	106.2 (16)
C3b—C3a—C8a	101.31 (12)	H92—C9—H93	108.7 (17)
C3—C3a—C8a	106.02 (13)	C6—C10—H101	109.8 (11)
C3b—C3a—H3A	111.8 (10)	C6—C10—H102	111.3 (11)
C3—C3a—H3A	111.4 (10)	H101—C10—H102	109.3 (15)
C8a—C3a—H3A	110.9 (10)	C6—C10—H103	109.0 (11)
C7a—C3b—C4	121.34 (15)	H101—C10—H103	108.5 (15)
C7a—C3b—C3a	110.20 (14)	H102—C10—H103	108.9 (15)
C4—C3b—C3a	128.45 (14)	C8a—C11—H111	110.4 (12)
O4—C4—C3b	122.94 (15)	C8a—C11—H112	110.8 (12)
O4—C4—C5	121.70 (15)	H111—C11—H112	107.6 (16)
C3b—C4—C5	115.34 (14)	C8a—C11—H113	109.5 (12)
C4—C5—C6	115.74 (13)	H111—C11—H113	109.5 (17)
C4—C5—H51	105.0 (12)	H112—C11—H113	109.1 (17)
C6—C5—H51	111.6 (12)	C13—C12—C17	120.45 (16)
C4—C5—H52	108.9 (11)	C13—C12—N1	119.28 (15)
C6—C5—H52	109.9 (11)	C17—C12—N1	120.26 (15)
H51—C5—H52	105.1 (16)	C14—C13—C12	119.66 (17)
C10—C6—C9	109.47 (14)	C14—C13—H13	120.7 (12)
C10—C6—C5	109.85 (14)	C12—C13—H13	119.7 (11)
C9—C6—C5	109.47 (13)	C15—C14—C13	120.45 (17)
C10—C6—C7	109.56 (13)	C15—C14—H14	119.1 (12)
C9—C6—C7	108.66 (13)	C13—C14—H14	120.5 (12)
C5—C6—C7	109.81 (13)	C14—C15—C16	119.60 (16)
C7a—C7—C6	111.06 (13)	C14—C15—H15	121.7 (13)
C7a—C7—H71	111.0 (11)	C16—C15—H15	118.7 (13)
C6—C7—H71	109.9 (11)	C15—C16—C17	120.55 (17)
C7a—C7—H72	108.0 (12)	C15—C16—H16	120.4 (12)
C6—C7—H72	111.5 (12)	C17—C16—H16	119.0 (12)
H71—C7—H72	105.2 (16)	C12—C17—C16	119.29 (16)
C3b—C7a—O8	114.40 (14)	C12—C17—H17	119.8 (11)
C3b—C7a—C7	126.84 (15)	C16—C17—H17	120.9 (11)

C12—N1—C2—O2	6.6 (3)	C3b—C7a—O8—C8a	−1.99 (18)
C8a—N1—C2—O2	−179.12 (15)	C7—C7a—O8—C8a	177.73 (13)
C12—N1—C2—C3	−171.82 (14)	C2—N1—C8a—O8	115.76 (14)
C8a—N1—C2—C3	2.48 (19)	C12—N1—C8a—O8	−69.88 (18)
O2—C2—C3—C3a	175.55 (16)	C2—N1—C8a—C11	−126.03 (16)
N1—C2—C3—C3a	−6.09 (18)	C12—N1—C8a—C11	48.3 (2)
C2—C3—C3a—C3b	−103.74 (16)	C2—N1—C8a—C3a	2.19 (17)
C2—C3—C3a—C8a	7.19 (17)	C12—N1—C8a—C3a	176.54 (14)
C3—C3a—C3b—C7a	113.68 (16)	C7a—O8—C8a—N1	−110.43 (14)
C8a—C3a—C3b—C7a	−0.04 (17)	C7a—O8—C8a—C11	127.08 (14)
C3—C3a—C3b—C4	−67.8 (2)	C7a—O8—C8a—C3a	1.83 (16)
C8a—C3a—C3b—C4	178.44 (16)	C3b—C3a—C8a—N1	114.34 (13)
C7a—C3b—C4—O4	174.77 (15)	C3—C3a—C8a—N1	−5.80 (16)
C3a—C3b—C4—O4	−3.6 (3)	C3b—C3a—C8a—O8	−1.06 (15)
C7a—C3b—C4—C5	−6.7 (2)	C3—C3a—C8a—O8	−121.20 (13)
C3a—C3b—C4—C5	174.97 (15)	C3b—C3a—C8a—C11	−119.63 (15)
O4—C4—C5—C6	−149.83 (15)	C3—C3a—C8a—C11	120.23 (16)
C3b—C4—C5—C6	31.6 (2)	C2—N1—C12—C13	56.7 (2)
C4—C5—C6—C10	70.11 (18)	C8a—N1—C12—C13	−117.21 (17)
C4—C5—C6—C9	−169.66 (14)	C2—N1—C12—C17	−124.69 (18)
C4—C5—C6—C7	−50.45 (19)	C8a—N1—C12—C17	61.4 (2)
C10—C6—C7—C7a	−76.86 (17)	C17—C12—C13—C14	−0.1 (3)
C9—C6—C7—C7a	163.57 (14)	N1—C12—C13—C14	178.51 (16)
C5—C6—C7—C7a	43.87 (18)	C12—C13—C14—C15	0.1 (3)
C4—C3b—C7a—O8	−177.32 (14)	C13—C14—C15—C16	−0.3 (3)
C3a—C3b—C7a—O8	1.29 (19)	C14—C15—C16—C17	0.5 (3)
C4—C3b—C7a—C7	3.0 (3)	C13—C12—C17—C16	0.3 (3)
C3a—C3b—C7a—C7	−178.41 (15)	N1—C12—C17—C16	−178.33 (15)
C6—C7—C7a—C3b	−22.9 (2)	C15—C16—C17—C12	−0.5 (3)
C6—C7—C7a—O8	157.41 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C17—H17···O8	1.00 (2)	2.49 (2)	3.066 (2)	116 (2)
C7—H72···O2ⁱ	0.96 (2)	2.49 (2)	3.275 (2)	140 (2)
C16—H16···O2ⁱⁱ	0.98 (2)	2.46 (2)	3.243 (3)	138 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z.

(III) 6,6,8a-trimethyl-1-(3-pyridyl)-3a,6,7,8a-tetrahydro- 1H-[1]benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione top

Crystal data top

C₁₈H₂₀N₂O₃	Z = 2
M_r = 312.36	F(000) = 332
Triclinic, P1	D_x = 1.333 Mg m⁻³
Hall symbol: -P 1	Melting point: 198(1) K
a = 7.2330 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.8165 (3) Å	Cell parameters from 3489 reflections
c = 11.6008 (3) Å	θ = 2.9–27.5°
α = 78.541 (2)°	µ = 0.09 mm⁻¹
β = 78.992 (2)°	T = 120 K
γ = 77.302 (1)°	Prism, colourless
V = 778.13 (4) Å³	0.19 × 0.14 × 0.09 mm

Data collection top

Nonius KappaCCD area-detector diffractometer	3040 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode	2769 reflections with I > 2σ(I)
10 cm confocal mirrors monochromator	R_int = 0.035
Detector resolution: 9.091 pixels mm^-1	θ_max = 26.0°, θ_min = 3.0°
ϕ and ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −12→12
T_min = 0.913, T_max = 0.992	l = −14→13
13914 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.039	Hydrogen site location: difference Fourier map
wR(F²) = 0.104	All H-atom parameters refined
S = 1.07	w = 1/[σ²(F_o²) + (0.0478P)² + 0.3717P] where P = (F_o² + 2F_c²)/3
3040 reflections	(Δ/σ)_max = 0.006
288 parameters	Δρ_max = 0.29 e Å⁻³
0 restraints	Δρ_min = −0.20 e Å⁻³

Crystal data top

C₁₈H₂₀N₂O₃	γ = 77.302 (1)°
M_r = 312.36	V = 778.13 (4) Å³
Triclinic, P1	Z = 2
a = 7.2330 (2) Å	Mo Kα radiation
b = 9.8165 (3) Å	µ = 0.09 mm⁻¹
c = 11.6008 (3) Å	T = 120 K
α = 78.541 (2)°	0.19 × 0.14 × 0.09 mm
β = 78.992 (2)°

Data collection top

Nonius KappaCCD area-detector diffractometer	3040 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	2769 reflections with I > 2σ(I)
T_min = 0.913, T_max = 0.992	R_int = 0.035
13914 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	0 restraints
wR(F²) = 0.104	All H-atom parameters refined
S = 1.07	Δρ_max = 0.29 e Å⁻³
3040 reflections	Δρ_min = −0.20 e Å⁻³
288 parameters

Special details top

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.52665 (16)	0.30837 (12)	0.41917 (10)	0.0176 (3)
C2	0.33267 (19)	0.36189 (14)	0.43603 (12)	0.0192 (3)
O2	0.23076 (14)	0.35965 (11)	0.53250 (9)	0.0266 (3)
C3	0.2698 (2)	0.41948 (16)	0.31608 (12)	0.0212 (3)
H31	0.199 (3)	0.522 (2)	0.3150 (16)	0.031 (4)*
H32	0.180 (3)	0.3629 (19)	0.3075 (16)	0.031 (4)*
C3a	0.45417 (18)	0.40606 (14)	0.22483 (12)	0.0175 (3)
H3A	0.445 (2)	0.3544 (17)	0.1614 (14)	0.020 (4)*
C3b	0.52623 (18)	0.54125 (14)	0.17524 (11)	0.0169 (3)
C4	0.44123 (18)	0.66200 (14)	0.09692 (11)	0.0179 (3)
O4	0.29262 (14)	0.66625 (11)	0.05789 (9)	0.0253 (3)
C5	0.54395 (19)	0.78688 (14)	0.06719 (13)	0.0197 (3)
H51	0.484 (2)	0.8465 (19)	0.1277 (16)	0.029 (4)*
H52	0.512 (2)	0.8426 (19)	−0.0123 (16)	0.031 (4)*
C6	0.76353 (18)	0.74878 (13)	0.06428 (11)	0.0163 (3)
C7	0.81269 (19)	0.64704 (14)	0.17855 (12)	0.0172 (3)
H71	0.951 (3)	0.6059 (18)	0.1696 (15)	0.026 (4)*
H72	0.790 (2)	0.6981 (17)	0.2473 (15)	0.024 (4)*
C7a	0.69611 (18)	0.53467 (14)	0.20903 (11)	0.0156 (3)
O8	0.76186 (13)	0.41105 (10)	0.27684 (8)	0.0178 (2)
C8a	0.61651 (19)	0.32125 (14)	0.29524 (11)	0.0176 (3)
C9	0.8411 (2)	0.88351 (15)	0.05682 (14)	0.0231 (3)
H91	0.981 (3)	0.8597 (18)	0.0549 (15)	0.027 (4)*
H92	0.785 (3)	0.931 (2)	0.1271 (17)	0.033 (5)*
H93	0.812 (3)	0.9530 (19)	−0.0187 (17)	0.030 (4)*
C10	0.8581 (2)	0.67893 (15)	−0.04465 (12)	0.0187 (3)
H101	0.827 (2)	0.7468 (18)	−0.1199 (15)	0.024 (4)*
H102	0.813 (2)	0.5911 (18)	−0.0417 (14)	0.021 (4)*
H103	1.000 (2)	0.6569 (18)	−0.0462 (15)	0.025 (4)*
C11	0.7167 (2)	0.18111 (15)	0.25856 (13)	0.0230 (3)
H111	0.822 (3)	0.1352 (19)	0.3050 (17)	0.033 (5)*
H112	0.770 (3)	0.1982 (19)	0.1741 (17)	0.031 (4)*
H113	0.622 (3)	0.1204 (19)	0.2701 (16)	0.030 (4)*
C12	0.62667 (19)	0.23041 (14)	0.51338 (12)	0.0194 (3)
C13	0.5574 (2)	0.11635 (16)	0.58656 (13)	0.0246 (3)
H13	0.434 (3)	0.0919 (18)	0.5760 (15)	0.028 (4)*
N14	0.64495 (19)	0.03434 (14)	0.67481 (12)	0.0292 (3)
C15	0.8073 (2)	0.06686 (17)	0.69164 (13)	0.0282 (3)
H15	0.871 (3)	0.0038 (19)	0.7574 (17)	0.033 (5)*
C16	0.8863 (2)	0.17848 (17)	0.62335 (13)	0.0278 (3)
H16	1.002 (3)	0.197 (2)	0.6422 (18)	0.041 (5)*
C17	0.7942 (2)	0.26320 (16)	0.53253 (13)	0.0239 (3)
H17	0.843 (3)	0.346 (2)	0.4835 (16)	0.032 (5)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0170 (6)	0.0212 (6)	0.0135 (5)	−0.0048 (4)	−0.0015 (4)	0.0000 (4)
C2	0.0192 (7)	0.0203 (7)	0.0186 (7)	−0.0073 (5)	−0.0019 (5)	−0.0013 (5)
O2	0.0218 (5)	0.0363 (6)	0.0179 (5)	−0.0046 (4)	0.0027 (4)	−0.0022 (4)
C3	0.0159 (7)	0.0304 (8)	0.0176 (7)	−0.0084 (6)	−0.0024 (5)	−0.0005 (6)
C3a	0.0172 (7)	0.0217 (7)	0.0147 (6)	−0.0079 (5)	−0.0026 (5)	−0.0011 (5)
C3b	0.0163 (6)	0.0202 (7)	0.0145 (6)	−0.0062 (5)	−0.0003 (5)	−0.0023 (5)
C4	0.0134 (6)	0.0230 (7)	0.0159 (6)	−0.0020 (5)	0.0006 (5)	−0.0037 (5)
O4	0.0169 (5)	0.0323 (6)	0.0262 (5)	−0.0060 (4)	−0.0074 (4)	0.0018 (4)
C5	0.0161 (7)	0.0182 (7)	0.0228 (7)	−0.0013 (5)	−0.0017 (5)	−0.0017 (6)
C6	0.0149 (6)	0.0163 (6)	0.0175 (6)	−0.0032 (5)	−0.0025 (5)	−0.0018 (5)
C7	0.0158 (7)	0.0210 (7)	0.0158 (6)	−0.0058 (5)	−0.0028 (5)	−0.0027 (5)
C7a	0.0165 (6)	0.0180 (6)	0.0110 (6)	−0.0025 (5)	−0.0003 (5)	−0.0019 (5)
O8	0.0159 (5)	0.0190 (5)	0.0183 (5)	−0.0063 (4)	−0.0038 (4)	0.0021 (4)
C8a	0.0171 (6)	0.0209 (7)	0.0153 (6)	−0.0088 (5)	−0.0001 (5)	−0.0009 (5)
C9	0.0230 (7)	0.0175 (7)	0.0294 (8)	−0.0065 (6)	−0.0047 (6)	−0.0019 (6)
C10	0.0174 (7)	0.0215 (7)	0.0168 (7)	−0.0054 (5)	−0.0014 (5)	−0.0016 (5)
C11	0.0242 (7)	0.0213 (7)	0.0219 (7)	−0.0057 (6)	0.0023 (6)	−0.0037 (6)
C12	0.0200 (7)	0.0212 (7)	0.0157 (6)	−0.0023 (5)	−0.0015 (5)	−0.0028 (5)
C13	0.0241 (7)	0.0250 (7)	0.0235 (7)	−0.0060 (6)	−0.0030 (6)	−0.0002 (6)
N14	0.0289 (7)	0.0285 (7)	0.0257 (7)	−0.0057 (5)	−0.0028 (5)	0.0053 (5)
C15	0.0227 (7)	0.0333 (8)	0.0218 (7)	0.0012 (6)	−0.0017 (6)	0.0027 (6)
C16	0.0212 (7)	0.0364 (9)	0.0241 (7)	−0.0046 (6)	−0.0047 (6)	−0.0011 (6)
C17	0.0232 (7)	0.0273 (8)	0.0206 (7)	−0.0077 (6)	−0.0024 (6)	−0.0006 (6)

Geometric parameters (Å, º) top

N1—C2	1.3765 (18)	C7—H72	0.993 (17)
N1—C12	1.4247 (17)	C7a—O8	1.3518 (16)
N1—C8a	1.4535 (16)	O8—C8a	1.4748 (15)
C2—O2	1.2159 (17)	C8a—C11	1.5084 (19)
C2—C3	1.5096 (19)	C9—H91	0.987 (18)
C3—C3a	1.5348 (18)	C9—H92	0.996 (19)
C3—H31	1.024 (19)	C9—H93	1.023 (19)
C3—H32	0.972 (18)	C10—H101	1.017 (17)
C3a—C3b	1.5001 (18)	C10—H102	0.980 (17)
C3a—C8a	1.5508 (18)	C10—H103	1.001 (17)
C3a—H3A	0.991 (16)	C11—H111	0.990 (19)
C3b—C7a	1.3440 (18)	C11—H112	0.977 (19)
C3b—C4	1.4400 (19)	C11—H113	0.978 (18)
C4—O4	1.2332 (16)	C12—C17	1.387 (2)
C4—C5	1.5193 (19)	C12—C13	1.390 (2)
C5—C6	1.5450 (18)	C13—N14	1.339 (2)
C5—H51	0.979 (19)	C13—H13	1.011 (18)
C5—H52	1.014 (18)	N14—C15	1.340 (2)
C6—C9	1.5276 (18)	C15—C16	1.383 (2)
C6—C10	1.5307 (18)	C15—H15	0.999 (19)
C6—C7	1.5424 (18)	C16—C17	1.386 (2)
C7—C7a	1.4809 (18)	C16—H16	0.97 (2)
C7—H71	0.988 (18)	C17—H17	0.987 (19)

C2—N1—C12	122.90 (11)	C3b—C7a—C7	126.46 (12)
C2—N1—C8a	114.39 (11)	O8—C7a—C7	119.08 (11)
C12—N1—C8a	122.22 (11)	C7a—O8—C8a	107.46 (10)
O2—C2—N1	124.65 (13)	N1—C8a—O8	108.62 (10)
O2—C2—C3	126.56 (13)	N1—C8a—C11	113.18 (11)
N1—C2—C3	108.78 (11)	O8—C8a—C11	107.49 (11)
C2—C3—C3a	105.67 (11)	N1—C8a—C3a	104.53 (10)
C2—C3—H31	109.5 (10)	O8—C8a—C3a	106.66 (10)
C3a—C3—H31	112.7 (10)	C11—C8a—C3a	116.01 (11)
C2—C3—H32	106.5 (11)	C6—C9—H91	109.6 (10)
C3a—C3—H32	114.0 (10)	C6—C9—H92	111.7 (10)
H31—C3—H32	108.2 (14)	H91—C9—H92	107.4 (14)
C3b—C3a—C3	115.39 (11)	C6—C9—H93	110.7 (10)
C3b—C3a—C8a	101.22 (10)	H91—C9—H93	108.4 (14)
C3—C3a—C8a	106.03 (10)	H92—C9—H93	108.8 (14)
C3b—C3a—H3A	112.2 (9)	C6—C10—H101	109.4 (9)
C3—C3a—H3A	111.8 (9)	C6—C10—H102	111.0 (10)
C8a—C3a—H3A	109.3 (9)	H101—C10—H102	109.2 (13)
C7a—C3b—C4	121.61 (12)	C6—C10—H103	108.8 (10)
C7a—C3b—C3a	110.16 (12)	H101—C10—H103	109.3 (13)
C4—C3b—C3a	128.14 (12)	H102—C10—H103	109.2 (13)
O4—C4—C3b	122.78 (12)	C8a—C11—H111	111.4 (11)
O4—C4—C5	121.56 (12)	C8a—C11—H112	108.2 (10)
C3b—C4—C5	115.64 (11)	H111—C11—H112	109.2 (15)
C4—C5—C6	115.43 (11)	C8a—C11—H113	108.4 (10)
C4—C5—H51	105.2 (10)	H111—C11—H113	110.5 (15)
C6—C5—H51	110.6 (10)	H112—C11—H113	109.0 (14)
C4—C5—H52	107.6 (10)	C17—C12—C13	118.92 (13)
C6—C5—H52	110.3 (10)	C17—C12—N1	121.76 (12)
H51—C5—H52	107.2 (14)	C13—C12—N1	119.30 (12)
C9—C6—C10	109.13 (11)	N14—C13—C12	123.51 (14)
C9—C6—C7	108.67 (11)	N14—C13—H13	116.0 (10)
C10—C6—C7	109.63 (11)	C12—C13—H13	120.5 (10)
C9—C6—C5	109.37 (11)	C13—N14—C15	116.82 (13)
C10—C6—C5	109.79 (11)	N14—C15—C16	123.55 (14)
C7—C6—C5	110.22 (11)	N14—C15—H15	115.5 (10)
C7a—C7—C6	111.02 (10)	C16—C15—H15	120.9 (10)
C7a—C7—H71	111.0 (10)	C15—C16—C17	119.23 (14)
C6—C7—H71	110.4 (10)	C15—C16—H16	118.9 (12)
C7a—C7—H72	108.4 (10)	C17—C16—H16	121.8 (12)
C6—C7—H72	111.4 (10)	C16—C17—C12	117.96 (14)
H71—C7—H72	104.5 (14)	C16—C17—H17	121.7 (10)
C3b—C7a—O8	114.46 (12)	C12—C17—H17	120.3 (10)

C12—N1—C2—O2	6.8 (2)	C3b—C7a—O8—C8a	−1.64 (14)
C8a—N1—C2—O2	178.94 (13)	C7—C7a—O8—C8a	178.71 (11)
C12—N1—C2—C3	−171.98 (12)	C2—N1—C8a—O8	118.20 (12)
C8a—N1—C2—C3	0.17 (16)	C12—N1—C8a—O8	−69.59 (15)
O2—C2—C3—C3a	176.29 (14)	C2—N1—C8a—C11	−122.50 (13)
N1—C2—C3—C3a	−4.97 (15)	C12—N1—C8a—C11	49.71 (17)
C2—C3—C3a—C3b	−103.61 (13)	C2—N1—C8a—C3a	4.63 (14)
C2—C3—C3a—C8a	7.53 (14)	C12—N1—C8a—C3a	176.84 (11)
C3—C3a—C3b—C7a	114.58 (13)	C7a—O8—C8a—N1	−110.22 (11)
C8a—C3a—C3b—C7a	0.63 (14)	C7a—O8—C8a—C11	126.99 (11)
C3—C3a—C3b—C4	−68.84 (17)	C7a—O8—C8a—C3a	1.94 (13)
C8a—C3a—C3b—C4	177.22 (13)	C3b—C3a—C8a—N1	113.43 (11)
C7a—C3b—C4—O4	174.65 (12)	C3—C3a—C8a—N1	−7.36 (13)
C3a—C3b—C4—O4	−1.6 (2)	C3b—C3a—C8a—O8	−1.52 (12)
C7a—C3b—C4—C5	−6.80 (18)	C3—C3a—C8a—O8	−122.31 (11)
C3a—C3b—C4—C5	176.96 (12)	C3b—C3a—C8a—C11	−121.20 (12)
O4—C4—C5—C6	−150.29 (12)	C3—C3a—C8a—C11	118.01 (13)
C3b—C4—C5—C6	31.15 (16)	C2—N1—C12—C17	−130.19 (15)
C4—C5—C6—C9	−169.41 (11)	C8a—N1—C12—C17	58.26 (18)
C4—C5—C6—C10	70.87 (14)	C2—N1—C12—C13	51.31 (18)
C4—C5—C6—C7	−50.00 (15)	C8a—N1—C12—C13	−120.23 (14)
C9—C6—C7—C7a	163.72 (11)	C17—C12—C13—N14	−0.7 (2)
C10—C6—C7—C7a	−77.08 (13)	N1—C12—C13—N14	177.84 (13)
C5—C6—C7—C7a	43.89 (14)	C12—C13—N14—C15	0.3 (2)
C4—C3b—C7a—O8	−176.24 (11)	C13—N14—C15—C16	−0.1 (2)
C3a—C3b—C7a—O8	0.61 (16)	N14—C15—C16—C17	0.4 (2)
C4—C3b—C7a—C7	3.4 (2)	C15—C16—C17—C12	−0.8 (2)
C3a—C3b—C7a—C7	−179.78 (12)	C13—C12—C17—C16	0.9 (2)
C6—C7—C7a—C3b	−23.15 (18)	N1—C12—C17—C16	−177.56 (13)
C6—C7—C7a—O8	156.45 (11)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C17—H17···O8	0.99 (2)	2.50 (2)	3.060 (2)	116 (2)
C7—H72···O2ⁱ	0.99 (2)	2.49 (2)	3.295 (2)	138 (1)
C16—H16···O2ⁱⁱ	0.97 (2)	2.54 (2)	3.268 (2)	132 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z.

Experimental details

	(I)	(II)	(III)
Crystal data
Chemical formula	C₁₉H₂₇NO₃	C₁₉H₂₁NO₃	C₁₈H₂₀N₂O₃
M_r	317.42	311.37	312.36
Crystal system, space group	Triclinic, P1	Triclinic, P1	Triclinic, P1
Temperature (K)	120	120	120
a, b, c (Å)	9.4708 (2), 10.2139 (2), 10.7512 (2)	7.2348 (2), 10.1212 (5), 11.6287 (6)	7.2330 (2), 9.8165 (3), 11.6008 (3)
α, β, γ (°)	105.804 (1), 99.141 (1), 116.320 (1)	77.031 (2), 79.285 (3), 76.872 (3)	78.541 (2), 78.992 (2), 77.302 (1)
V (Å³)	848.50 (3)	799.89 (6)	778.13 (4)
Z	2	2	2
Radiation type	Mo Kα	Mo Kα	Mo Kα
µ (mm⁻¹)	0.08	0.09	0.09
Crystal size (mm)	0.24 × 0.16 × 0.03	0.20 × 0.14 × 0.03	0.19 × 0.14 × 0.09

Data collection
Diffractometer	Nonius KappaCCD area-detector diffractometer	Nonius KappaCCD area-detector diffractometer	Nonius KappaCCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2003)	Multi-scan (SADABS; Sheldrick, 2003)	Multi-scan (SADABS; Sheldrick, 2003)
T_min, T_max	0.891, 0.998	0.903, 0.997	0.913, 0.992
No. of measured, independent and observed [I > 2σ(I)] reflections	18064, 3327, 2990	14845, 3132, 2562	13914, 3040, 2769
R_int	0.039	0.047	0.035
(sin θ/λ)_max (Å⁻¹)	0.617	0.617	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.107, 1.12	0.044, 0.117, 1.07	0.039, 0.104, 1.07
No. of reflections	3327	3132	3040
No. of parameters	316	292	288
H-atom treatment	All H-atom parameters refined	All H-atom parameters refined	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.30, −0.32	0.19, −0.27	0.29, −0.20

Computer programs: COLLECT (Nonius, 1998), DENZO (Otwinowski & Minor, 1997) and COLLECT, DENZO and COLLECT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPIII (Farrugia, 1997), PLATON (Spek, 2003) and INSIGHTII (Accelrys, 2002), SHELXL97 and PLATON).

Hydrogen-bond geometry (Å, º) for (I) top

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···O8	1.00 (2)	2.52 (2)	2.920 (2)	103 (1)
C17—H171···O2	1.01 (2)	2.55 (2)	3.153 (2)	118 (1)

Hydrogen-bond geometry (Å, º) for (II) top

D—H···A	D—H	H···A	D···A	D—H···A
C17—H17···O8	1.00 (2)	2.49 (2)	3.066 (2)	116 (2)
C7—H72···O2ⁱ	0.96 (2)	2.49 (2)	3.275 (2)	140 (2)
C16—H16···O2ⁱⁱ	0.98 (2)	2.46 (2)	3.243 (3)	138 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z.

Hydrogen-bond geometry (Å, º) for (III) top

D—H···A	D—H	H···A	D···A	D—H···A
C17—H17···O8	0.99 (2)	2.50 (2)	3.060 (2)	116 (2)
C7—H72···O2ⁱ	0.99 (2)	2.49 (2)	3.295 (2)	138 (1)
C16—H16···O2ⁱⁱ	0.97 (2)	2.54 (2)	3.268 (2)	132 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z.

Acknowledgements

The authors thank the EPSRC National Crystallography Service, Southampton, England.

References

Accelrys (2002). INSIGHTII. Version 2000.2. Accelrys Inc., 9685 Scranton Road, San Diego, CA 92121-3752, USA. Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bucourt, R. (1974). Topics in Stereochemistry, Vol. 8, edited by E. L. Eliel & N. Allinger, pp. 159–224. New York: John Wiley. Google Scholar
Cahn, R. S., Ingold, C. K. & Prelog, V. (1966). Angew. Chem. Int. Ed. Engl. 5, 385–415. CrossRef CAS Web of Science Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond in Structural Chemistry and Biology. New York: Oxford University Press Inc. Google Scholar
Duax, W. L., Weeks, C. M. & Rohrer, D. C. (1976). Topics in Stereochemistry, Vol. 9, edited by E. L. Eliel & N. Allinger, pp. 271–383. New York: John Wiley. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Fuchs, B. (1978). Topics in Stereochemistry, Vol. 10, edited by E. L. Eliel & N. Allinger, pp. 1–94. New York: John Wiley. Google Scholar
Kálmán, A., Párkányi, L. & Argay, G. (1993). Acta Cryst. B49, 1039–1049. CrossRef Web of Science IUCr Journals Google Scholar
Nagaraj, B., Yathirajan, H. S., Nagaraja, P. & Lynch, D. E. (2005). Acta Cryst. E61, o1041–o1042. Web of Science CSD CrossRef IUCr Journals Google Scholar
Nagarajan, K., Talwalker, P. K., Nagana Goud, A., Shah, R. K., Shenoy, S. J. & Desai, N. D. (1988). Indian J. Chem. Sect. B, 27, 1113–1123. Google Scholar
Narasegowda, R. S., Yathirajan, H. S., Lynch, D. E., Narasimhamurthy, T. & Rathore, R. S. (2006). Acta Cryst. E62, o1328–o1329. Web of Science CSD CrossRef IUCr Journals Google Scholar
Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Sharma, C. V. K. & Desiraju, G. R. (1994). J. Chem. Soc. Perkin Trans. 2, pp. 2345–2352. CSD CrossRef Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2003). SADABS. Version 2.10. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar

© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.

STRUCTURAL
CHEMISTRY

ISSN: 2053-2296

Volume 62| Part 5| May 2006| Pages o277-o280

doi:10.1107/S010827010601119X

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text
		Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text
		Text

Search term		doi		Advanced search
Author		volume	page

organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Conformations of three heterocyclic perhydro­pyrrolobenzo­furans and polymeric assembly via co-operative inter­molecular C—H⋯O hydrogen bonds

Comment

Experimental

Compound (I)

Crystal data

Data collection

Refinement

Compound (II)

Crystal data

Data collection

Refinement

Compound (III)

Crystal data

Data collection

Refinement

Supporting information

Acknowledgements

References

organic compounds

Conformations of three heterocyclic perhydropyrrolobenzofurans and polymeric assembly via co-operative intermolecular C—H⋯O hydrogen bonds