cis-3,3-Dimethyl-3,3a,4,5,6,6a-hexa­hydro-1H-cyclo­penta­[c]furan-1,6-dione

Pearson, W.H.; Lanham, S.E.; Dillner, D.K.

doi:10.1107/S1600536808017133

organic compounds

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ISSN: 2056-9890

Volume 64| Part 7| July 2008| Page o1266

doi:10.1107/S1600536808017133

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cis-3,3-Dimethyl-3,3a,4,5,6,6a-hexahydro-1H-cyclopenta[c]furan-1,6-dione

Wayne H. Pearson,^a ^* Stacey E. Lanham ^a and Debra K. Dillner ^a

^aChemistry Department, United States Naval Academy, 572M Holloway Road, Annapolis, Maryland 21402, USA
^*Correspondence e-mail: wpearson@usna.edu

(Received 29 May 2008; accepted 6 June 2008; online 13 June 2008)

The bicyclic molecule of the title compound, C₉H₁₂O₃, contains two five-membered rings with different functional groups, viz. a ketone and an ester. Both rings assume an envelope conformation. The mean planes of these functional groups form a dihedral angle of 60.7 (1)°. The crystal structure exhibits weak intermolecular C—H⋯O interactions, which link the molecules into zigzag chains extended in the [010] direction. The unit cell contains a racemic mixture of enantiomers.

Related literature

For related literature, see: Boeckman et al. (1989 ); Wang et al. (2006 ); Rodriguez (1998 ); Corey & Kang (1984 ).

Experimental

Crystal data

C₉H₁₂O₃
M_r = 168.19
Triclinic, $[P \overline 1]$
a = 6.7333 (7) Å
b = 8.2897 (8) Å
c = 8.5906 (8) Å
α = 111.657 (2)°
β = 103.571 (2)°
γ = 92.809 (2)°
V = 428.30 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 173 (2) K
0.33 × 0.16 × 0.13 mm

Data collection

Bruker Kappa APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ) T_min = 0.934, T_max = 0.988
9157 measured reflections
1961 independent reflections
1632 reflections with I > 2σ(I)
R_int = 0.067

Refinement

R[F² > 2σ(F²)] = 0.038
wR(F²) = 0.107
S = 1.06
1961 reflections
111 parameters
H-atom parameters constrained
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯O3ⁱ	1.00	2.51	3.3418 (13)	140
C4—H4B⋯O2ⁱⁱ	0.99	2.51	3.4821 (16)	166
Symmetry codes: (i) -x+2, -y, -z+1; (ii) -x+2, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808017133/cv2418sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808017133/cv2418Isup2.hkl

checkCIF report

Comment top

Cyclopentane rings bearing multiple stereocenters are a common motif in terpenes, including ceroplastol (Boeckman et al., 1989) and dolabellanes. (Wang et al., 2006) Due to the wide variety of biological activities shown by these terpenes, interest in their synthesis is high. (Rodriguez, 1998) The bicyclic nature of the title compound makes it conformationally rigid. This rigidity is essential to its use as a stereochemical control element. Subsequent transformations require that one face of the molecule be more accessible than the other. For this reason, obtaining a crystal structure was an important goal.

The more accessible face of the molecule is oriented on the top side of figure 1. The angle between least-squares planes defined by the ketone and ester functional groups is 60.7 (1) degrees. Bond distances in this compound are quite reasonable when compared with expected values. The carbon-carbon bonds average 1.528 (10) Å in length. The two carbonyl bonds have an average length of 1.206 (2) Å while the ring oxygen, O1, is positioned 1.344 (1) Å from C1 and 1.488 (1) Å from C2. Strain in the ring system is observed in the bond angles on opposite sides of the molecule. Angles on the carbonyl side of the compound are considerably less than the expected 120 ° for an sp² hybridized carbon. The angle defined by C4—C5—C6 is 107.93 (9) ° while the O1—C1—C6 angle is 110.06 (8) °. On the opposite side of the ring system, the C3—C7—C2 angle is more open at 117.00 (9) ° rather than the 109.5 ° that would expected around an sp³ hybridized, central atom.

Related literature top

For related literature, see: Boeckman et al. (1989); Wang et al. (2006); Rodriguez (1998); Corey & Kang (1984).

Experimental top

As part of a synthetic effort to prepare natural products, the title compound was prepared in a manner similar to that described by Corey & Kang (1984). Crystals were obtained by evaporation from ethanol.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 (Bruker, 2007); data reduction: APEX2 (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of the title compound, with atom labels and 50% probability displacement ellipsoids for non-H atoms.

cis-3,3-Dimethyl-3,3a,4,5,6,6a-tetrahydro-1H- cyclopenta[c]furan-1,6-dione top

Crystal data top

C₉H₁₂O₃	Z = 2
M_r = 168.19	F(000) = 180
Triclinic, P1	D_x = 1.304 Mg m⁻³ D_m = 1.258 Mg m⁻³ D_m measured by flotation
Hall symbol: -P 1	Melting point = 355–357 K
a = 6.7333 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.2897 (8) Å	Cell parameters from 4358 reflections
c = 8.5906 (8) Å	θ = 2.7–27.5°
α = 111.657 (2)°	µ = 0.10 mm⁻¹
β = 103.571 (2)°	T = 173 K
γ = 92.809 (2)°	Regular parallelepiped, colourless
V = 428.30 (7) Å³	0.33 × 0.16 × 0.13 mm

Data collection top

Bruker KAPPA APEXII diffractometer	1961 independent reflections
Radiation source: fine-focus sealed tube	1632 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.067
Detector resolution: 512 pixels mm^-1	θ_max = 27.5°, θ_min = 2.7°
combination of ω and ϕ scans	h = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 2007)	k = −10→10
T_min = 0.934, T_max = 0.988	l = −11→11
9157 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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.108	H-atom parameters constrained
S = 1.06	w = 1/[σ²(F_o²) + (0.057P)² + 0.0541P] where P = (F_o² + 2F_c²)/3
1961 reflections	(Δ/σ)_max < 0.001
111 parameters	Δρ_max = 0.34 e Å⁻³
0 restraints	Δρ_min = −0.16 e Å⁻³

Crystal data top

C₉H₁₂O₃	γ = 92.809 (2)°
M_r = 168.19	V = 428.30 (7) Å³
Triclinic, P1	Z = 2
a = 6.7333 (7) Å	Mo Kα radiation
b = 8.2897 (8) Å	µ = 0.10 mm⁻¹
c = 8.5906 (8) Å	T = 173 K
α = 111.657 (2)°	0.33 × 0.16 × 0.13 mm
β = 103.571 (2)°

Data collection top

Bruker KAPPA APEXII diffractometer	1961 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2007)	1632 reflections with I > 2σ(I)
T_min = 0.934, T_max = 0.988	R_int = 0.067
9157 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.038	0 restraints
wR(F²) = 0.108	H-atom parameters constrained
S = 1.06	Δρ_max = 0.34 e Å⁻³
1961 reflections	Δρ_min = −0.16 e Å⁻³
111 parameters

Special details top

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
C1	1.03889 (16)	0.18603 (13)	0.76894 (14)	0.0248 (3)
C2	0.75616 (16)	0.19250 (14)	0.88370 (14)	0.0252 (3)
C3	0.67417 (18)	0.39922 (14)	0.71460 (15)	0.0295 (3)
H3A	0.5373	0.4352	0.7209	0.035*
H3B	0.7814	0.4840	0.8164	0.035*
C4	0.7176 (2)	0.38907 (16)	0.54419 (17)	0.0347 (3)
H4A	0.5888	0.3489	0.4478	0.042*
H4B	0.7811	0.5049	0.5563	0.042*
C5	0.86639 (18)	0.25662 (15)	0.51197 (15)	0.0291 (3)
C6	0.84742 (15)	0.14672 (13)	0.61779 (13)	0.0219 (2)
H6	0.8134	0.0185	0.5424	0.026*
C7	0.67906 (15)	0.21095 (13)	0.70880 (13)	0.0218 (2)
H7	0.5426	0.1354	0.6403	0.026*
C8	0.70323 (19)	0.32707 (17)	1.03822 (15)	0.0340 (3)
H8A	0.7730	0.3122	1.1447	0.051*
H8B	0.5534	0.3105	1.0213	0.051*
H8C	0.7491	0.4455	1.0484	0.051*
C9	0.6960 (2)	0.00625 (16)	0.86661 (18)	0.0367 (3)
H9A	0.7418	−0.0767	0.7715	0.055*
H9B	0.5455	−0.0191	0.8417	0.055*
H9C	0.7619	−0.0054	0.9757	0.055*
O1	0.98475 (11)	0.22286 (11)	0.91791 (10)	0.0297 (2)
O2	0.98035 (16)	0.23863 (12)	0.41910 (13)	0.0442 (3)
O3	1.21632 (12)	0.18858 (11)	0.76418 (12)	0.0374 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0204 (5)	0.0238 (5)	0.0290 (6)	0.0052 (4)	0.0081 (4)	0.0081 (4)
C2	0.0191 (5)	0.0320 (6)	0.0262 (6)	0.0068 (4)	0.0083 (4)	0.0115 (4)
C3	0.0307 (6)	0.0276 (6)	0.0334 (6)	0.0132 (4)	0.0132 (5)	0.0117 (5)
C4	0.0396 (7)	0.0349 (6)	0.0399 (7)	0.0161 (5)	0.0172 (6)	0.0211 (5)
C5	0.0317 (6)	0.0280 (5)	0.0307 (6)	0.0071 (4)	0.0131 (5)	0.0121 (5)
C6	0.0199 (5)	0.0204 (5)	0.0250 (5)	0.0046 (4)	0.0088 (4)	0.0067 (4)
C7	0.0174 (5)	0.0238 (5)	0.0228 (5)	0.0043 (4)	0.0066 (4)	0.0065 (4)
C8	0.0314 (6)	0.0449 (7)	0.0243 (6)	0.0107 (5)	0.0112 (5)	0.0091 (5)
C9	0.0382 (7)	0.0392 (7)	0.0457 (8)	0.0112 (5)	0.0213 (6)	0.0246 (6)
O1	0.0198 (4)	0.0411 (5)	0.0271 (4)	0.0078 (3)	0.0051 (3)	0.0124 (4)
O2	0.0564 (6)	0.0452 (5)	0.0526 (6)	0.0199 (4)	0.0381 (5)	0.0274 (5)
O3	0.0182 (4)	0.0444 (5)	0.0440 (5)	0.0058 (3)	0.0102 (4)	0.0097 (4)

Geometric parameters (Å, º) top

C1—O3	1.2043 (13)	C4—H4B	0.9900
C1—O1	1.3437 (13)	C5—O2	1.2076 (14)
C1—C6	1.5216 (15)	C5—C6	1.5255 (16)
C2—O1	1.4879 (12)	C6—C7	1.5322 (13)
C2—C8	1.5171 (15)	C6—H6	1.0000
C2—C9	1.5208 (16)	C7—H7	1.0000
C2—C7	1.5367 (16)	C8—H8A	0.9800
C3—C4	1.5325 (17)	C8—H8B	0.9800
C3—C7	1.5452 (15)	C8—H8C	0.9800
C3—H3A	0.9900	C9—H9A	0.9800
C3—H3B	0.9900	C9—H9B	0.9800
C4—C5	1.5162 (16)	C9—H9C	0.9800
C4—H4A	0.9900

O3—C1—O1	122.38 (11)	C1—C6—C7	103.11 (8)
O3—C1—C6	127.55 (11)	C5—C6—C7	106.73 (8)
O1—C1—C6	110.06 (8)	C1—C6—H6	111.5
O1—C2—C8	106.91 (9)	C5—C6—H6	111.5
O1—C2—C9	107.27 (9)	C7—C6—H6	111.5
C8—C2—C9	111.54 (10)	C6—C7—C2	103.16 (8)
O1—C2—C7	102.78 (8)	C6—C7—C3	103.53 (8)
C8—C2—C7	116.17 (9)	C2—C7—C3	117.00 (9)
C9—C2—C7	111.33 (9)	C6—C7—H7	110.8
C4—C3—C7	104.52 (9)	C2—C7—H7	110.8
C4—C3—H3A	110.8	C3—C7—H7	110.8
C7—C3—H3A	110.8	C2—C8—H8A	109.5
C4—C3—H3B	110.8	C2—C8—H8B	109.5
C7—C3—H3B	110.8	H8A—C8—H8B	109.5
H3A—C3—H3B	108.9	C2—C8—H8C	109.5
C5—C4—C3	104.25 (9)	H8A—C8—H8C	109.5
C5—C4—H4A	110.9	H8B—C8—H8C	109.5
C3—C4—H4A	110.9	C2—C9—H9A	109.5
C5—C4—H4B	110.9	C2—C9—H9B	109.5
C3—C4—H4B	110.9	H9A—C9—H9B	109.5
H4A—C4—H4B	108.9	C2—C9—H9C	109.5
O2—C5—C4	126.95 (11)	H9A—C9—H9C	109.5
O2—C5—C6	125.12 (10)	H9B—C9—H9C	109.5
C4—C5—C6	107.93 (9)	C1—O1—C2	110.98 (8)
C1—C6—C5	112.00 (9)

C7—C3—C4—C5	−34.23 (12)	O1—C2—C7—C6	30.96 (9)
C3—C4—C5—O2	−160.31 (13)	C8—C2—C7—C6	147.30 (9)
C3—C4—C5—C6	19.95 (13)	C9—C2—C7—C6	−83.58 (10)
O3—C1—C6—C5	−50.89 (15)	O1—C2—C7—C3	−81.93 (10)
O1—C1—C6—C5	127.96 (9)	C8—C2—C7—C3	34.42 (13)
O3—C1—C6—C7	−165.27 (11)	C9—C2—C7—C3	163.54 (9)
O1—C1—C6—C7	13.58 (11)	C4—C3—C7—C6	35.35 (11)
O2—C5—C6—C1	70.16 (15)	C4—C3—C7—C2	148.02 (9)
C4—C5—C6—C1	−110.10 (10)	O3—C1—O1—C2	−174.31 (10)
O2—C5—C6—C7	−177.71 (11)	C6—C1—O1—C2	6.77 (11)
C4—C5—C6—C7	2.03 (12)	C8—C2—O1—C1	−146.96 (10)
C1—C6—C7—C2	−27.21 (10)	C9—C2—O1—C1	93.29 (11)
C5—C6—C7—C2	−145.34 (9)	C7—C2—O1—C1	−24.16 (11)
C1—C6—C7—C3	95.19 (9)	H6—C6—C7—H7	−26.1
C5—C6—C7—C3	−22.94 (11)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···O3ⁱ	1.00	2.51	3.3418 (13)	140
C4—H4B···O2ⁱⁱ	0.99	2.51	3.4821 (16)	166

Symmetry codes: (i) −x+2, −y, −z+1; (ii) −x+2, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	C₉H₁₂O₃
M_r	168.19
Crystal system, space group	Triclinic, P1
Temperature (K)	173
a, b, c (Å)	6.7333 (7), 8.2897 (8), 8.5906 (8)
α, β, γ (°)	111.657 (2), 103.571 (2), 92.809 (2)
V (Å³)	428.30 (7)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.33 × 0.16 × 0.13

Data collection
Diffractometer	Bruker KAPPA APEXII diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2007)
T_min, T_max	0.934, 0.988
No. of measured, independent and observed [I > 2σ(I)] reflections	9157, 1961, 1632
R_int	0.067
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.108, 1.06
No. of reflections	1961
No. of parameters	111
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.34, −0.16

Computer programs: APEX2 (Bruker, 2007), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···O3ⁱ	1.00	2.51	3.3418 (13)	140.3
C4—H4B···O2ⁱⁱ	0.99	2.51	3.4821 (16)	165.8

Symmetry codes: (i) −x+2, −y, −z+1; (ii) −x+2, −y+1, −z+1.

Acknowledgements

The authors thank the Chemistry Department, United States Naval Academy, for supporting this work.

References

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