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

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(5S,6R)-6-Bromo-6-methyl-5-phenyl-3,4,5,6-tetra­hydro-2H-cyclo­penta­[b]pyran-7-one

aInstitute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany, and bInstitut für Anorganische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany
*Correspondence e-mail: bolte@chemie.uni-frankfurt.de

(Received 9 September 2011; accepted 19 September 2011; online 30 September 2011)

The title compound, C15H15BrO2, was synthesized by a Brønsted acid-catalysed domino electrocyclization-halogenation reaction. The five-membered ring is essentially planar (r.m.s. deviation 0.006 Å) and forms a dihedral angle of 72.7 (3)° with the attached phenyl ring. The six-membered heterocycle adopts a half-chair conformation. The crystal packing is stabilized by a C—H⋯O contact.

Related literature

For background information, see: Rueping & Ieawsuwan (2009[Rueping, M. & Ieawsuwan, W. (2009). Adv. Synth. Catal. 351, 78-84.]); Rueping et al. (2007[Rueping, M., Ieawsuwan, W., Antonchick, A. P. & Nachtsheim, B. J. (2007). Angew. Chem. Int. Ed. 46, 2097-2100.]). For the synthesis of the title compound, see: Rueping & Ieawsuwan (2011[Rueping, M. & Ieawsuwan, W. (2011). Chem. Commun., doi: 10.1039/C1CC15289K.]). For a comparable compound, see: Liang et al. (2003[Liang, G., Gradl, S. N. & Trauner, D. (2003). Org. Lett. 5, 4931-4934.]).

[Scheme 1]

Experimental

Crystal data
  • C15H15BrO2

  • Mr = 307.18

  • Orthorhombic, P 21 21 21

  • a = 9.2217 (11) Å

  • b = 11.5041 (12) Å

  • c = 12.9149 (17) Å

  • V = 1370.1 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 2.99 mm−1

  • T = 173 K

  • 0.21 × 0.12 × 0.03 mm

Data collection
  • STOE IPDS II two-circle-diffractometer

  • Absorption correction: multi-scan (MULABS; Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]; Blessing, 1995[Blessing, R. H. (1995). Acta Cryst. A51, 33-38.]) Tmin = 0.572, Tmax = 0.916

  • 11129 measured reflections

  • 2407 independent reflections

  • 1849 reflections with I > 2σ(I)

  • Rint = 0.078

Refinement
  • R[F2 > 2σ(F2)] = 0.082

  • wR(F2) = 0.217

  • S = 1.03

  • 2407 reflections

  • 163 parameters

  • H-atom parameters constrained

  • Δρmax = 1.07 e Å−3

  • Δρmin = −1.13 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 1009 Friedel pairs

  • Flack parameter: 0.02 (3)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C1—H1⋯O31i 1.00 2.47 3.282 (9) 138
Symmetry code: (i) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: X-AREA (Stoe & Cie, 2001[Stoe & Cie (2001). X-AREA. Stoe & Cie, Darmstadt, Germany.]); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: XP (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Trans-4,5-substituted 5-bromocyclopentenone derivatives have been prepared by a organocatalyzed cascade protocol (Rueping & Ieawsuwan, 2009; Rueping et al., 2007). The Brønsted acid catalyzed domino electrocyclization-halogenation reaction provides for the first time, a variety of α-brominated cyclopent-2-enones with a wide substrate scope and with excellent enantioselectivities (Rueping & Ieawsuwan, 2011). Two chiral centers, a tertiary and a quaternary one, can be established during this transformation. The title compound was synthesized for the first time following this reaction and yellow needles suitable for crystal structure determination were obtained.

The five membered ring in the title compound is essentially planar (r.m.s. deviation 0.006 Å) and forms a dihedral angle of 72.7 (3)° with the attached phenyl ring. The six-membered heterocycle adopts a half chair conformation.

A comparable structure, cis-6-Methyl-5-phenyl-3,4,5,6-tetrahydro-2H-cyclopenta(b)pyran-7-one, with an H atom instead of a bromine residue (Liang et al., 2003) has essentially the same conformation (r.m.s. deviation for all C and O atoms 0.183 Å) (Fig. 2).

The crystal packing is stabilized by a C—H···O contact (Table 2).

Related literature top

For background information, see: Rueping & Ieawsuwan (2009); Rueping et al. (2007). For the synthesis of the title compound, see: Rueping & Ieawsuwan (2011). For a comparable compound, see: Liang et al. (2003).

Experimental top

The title compound has been synthesized as described by Rueping & Ieawsuwan (2011).

Refinement top

All H atoms could be located by difference Fourier synthesis. They were refined with fixed individual displacement parameters [U(H) = 1.2 Ueq(C) or U(H) = 1.5 Ueq(Cmethyl)] using a riding model with C—H ranging from 0.95Å to 1.00 Å.

Structure description top

Trans-4,5-substituted 5-bromocyclopentenone derivatives have been prepared by a organocatalyzed cascade protocol (Rueping & Ieawsuwan, 2009; Rueping et al., 2007). The Brønsted acid catalyzed domino electrocyclization-halogenation reaction provides for the first time, a variety of α-brominated cyclopent-2-enones with a wide substrate scope and with excellent enantioselectivities (Rueping & Ieawsuwan, 2011). Two chiral centers, a tertiary and a quaternary one, can be established during this transformation. The title compound was synthesized for the first time following this reaction and yellow needles suitable for crystal structure determination were obtained.

The five membered ring in the title compound is essentially planar (r.m.s. deviation 0.006 Å) and forms a dihedral angle of 72.7 (3)° with the attached phenyl ring. The six-membered heterocycle adopts a half chair conformation.

A comparable structure, cis-6-Methyl-5-phenyl-3,4,5,6-tetrahydro-2H-cyclopenta(b)pyran-7-one, with an H atom instead of a bromine residue (Liang et al., 2003) has essentially the same conformation (r.m.s. deviation for all C and O atoms 0.183 Å) (Fig. 2).

The crystal packing is stabilized by a C—H···O contact (Table 2).

For background information, see: Rueping & Ieawsuwan (2009); Rueping et al. (2007). For the synthesis of the title compound, see: Rueping & Ieawsuwan (2011). For a comparable compound, see: Liang et al. (2003).

Computing details top

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Perspective view of the title compound with the atom numbering scheme and displacement ellipsoids at the 50% probability level.
[Figure 2] Fig. 2. Least-squares fit of the title compound (open bonds) with cis-6-Methyl-5-phenyl-3,4,5,6-tetrahydro-2H-cyclopenta(b)pyran-7-one (full bonds).
(5S,6R)-6-Bromo-6-methyl-5-phenyl-3,4,5,6-tetrahydro-2H- cyclopenta[b]pyran-7-one top
Crystal data top
C15H15BrO2F(000) = 624
Mr = 307.18Dx = 1.489 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 7315 reflections
a = 9.2217 (11) Åθ = 3.6–25.5°
b = 11.5041 (12) ŵ = 2.99 mm1
c = 12.9149 (17) ÅT = 173 K
V = 1370.1 (3) Å3Needle, colourless
Z = 40.21 × 0.12 × 0.03 mm
Data collection top
STOE IPDS II two-circle-
diffractometer
2407 independent reflections
Radiation source: fine-focus sealed tube1849 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.078
ω scansθmax = 25.0°, θmin = 3.5°
Absorption correction: multi-scan
(MULABS; Spek, 2009; Blessing, 1995)
h = 1010
Tmin = 0.572, Tmax = 0.916k = 1313
11129 measured reflectionsl = 1515
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.082H-atom parameters constrained
wR(F2) = 0.217 w = 1/[σ2(Fo2) + (0.1273P)2 + 1.2132P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max < 0.001
2407 reflectionsΔρmax = 1.07 e Å3
163 parametersΔρmin = 1.13 e Å3
0 restraintsAbsolute structure: Flack (1983), 1009 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.02 (3)
Crystal data top
C15H15BrO2V = 1370.1 (3) Å3
Mr = 307.18Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 9.2217 (11) ŵ = 2.99 mm1
b = 11.5041 (12) ÅT = 173 K
c = 12.9149 (17) Å0.21 × 0.12 × 0.03 mm
Data collection top
STOE IPDS II two-circle-
diffractometer
2407 independent reflections
Absorption correction: multi-scan
(MULABS; Spek, 2009; Blessing, 1995)
1849 reflections with I > 2σ(I)
Tmin = 0.572, Tmax = 0.916Rint = 0.078
11129 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.082H-atom parameters constrained
wR(F2) = 0.217Δρmax = 1.07 e Å3
S = 1.03Δρmin = 1.13 e Å3
2407 reflectionsAbsolute structure: Flack (1983), 1009 Friedel pairs
163 parametersAbsolute structure parameter: 0.02 (3)
0 restraints
Special details top

Experimental. ;

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
xyzUiso*/Ueq
Br10.4532 (2)0.30553 (14)0.06794 (12)0.1312 (10)
C10.6283 (9)0.3284 (6)0.2534 (5)0.0310 (16)
H10.59880.24570.24220.037*
C20.5646 (11)0.4039 (7)0.1618 (5)0.0404 (19)
C30.4546 (10)0.4875 (6)0.2110 (6)0.0343 (17)
C40.4544 (9)0.4612 (5)0.3206 (5)0.0278 (15)
C50.5450 (10)0.3752 (6)0.3462 (5)0.0307 (17)
C60.5505 (10)0.3268 (6)0.4533 (5)0.0369 (18)
H6A0.64080.35210.48800.044*
H6B0.55010.24080.45050.044*
C70.4190 (11)0.3697 (7)0.5144 (6)0.046 (2)
H7A0.33180.32570.49290.055*
H7B0.43480.35570.58920.055*
C80.3945 (10)0.4988 (7)0.4959 (6)0.040 (2)
H8A0.31210.52600.53860.048*
H8B0.48190.54270.51700.048*
O90.3636 (7)0.5214 (5)0.3851 (4)0.0397 (14)
C110.7886 (9)0.3324 (6)0.2644 (5)0.0289 (16)
C120.8645 (11)0.4156 (7)0.3217 (7)0.040 (2)
H120.81090.47240.35890.048*
C131.0115 (11)0.4188 (7)0.3266 (7)0.045 (2)
H131.05810.47780.36590.054*
C141.0948 (10)0.3360 (8)0.2742 (7)0.045 (2)
H141.19770.33660.27810.054*
C151.0224 (12)0.2534 (7)0.2169 (7)0.047 (2)
H151.07770.19840.17880.057*
C160.8782 (10)0.2473 (6)0.2126 (7)0.0346 (18)
H160.83360.18600.17480.042*
C210.6732 (16)0.4727 (19)0.0990 (12)0.137 (9)
H21A0.74340.41940.06750.206*
H21B0.72410.52740.14430.206*
H21C0.62250.51570.04440.206*
O310.3838 (9)0.5587 (5)0.1641 (5)0.0542 (18)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.1929 (19)0.1099 (10)0.0906 (10)0.1023 (12)0.1072 (11)0.0738 (9)
C10.035 (4)0.035 (4)0.022 (4)0.005 (3)0.001 (3)0.001 (3)
C20.044 (5)0.060 (5)0.018 (3)0.011 (4)0.003 (4)0.004 (3)
C30.038 (5)0.037 (4)0.028 (4)0.006 (3)0.009 (4)0.008 (3)
C40.026 (4)0.033 (3)0.024 (3)0.002 (3)0.003 (3)0.003 (3)
C50.039 (5)0.030 (3)0.023 (3)0.007 (3)0.004 (3)0.001 (3)
C60.050 (5)0.040 (4)0.021 (3)0.005 (4)0.003 (4)0.007 (3)
C70.052 (6)0.058 (5)0.028 (4)0.006 (4)0.011 (4)0.009 (3)
C80.049 (5)0.053 (4)0.019 (4)0.008 (4)0.010 (4)0.002 (3)
O90.042 (3)0.046 (3)0.031 (3)0.014 (3)0.005 (3)0.001 (2)
C110.031 (4)0.033 (4)0.023 (3)0.001 (3)0.006 (3)0.001 (3)
C120.047 (6)0.031 (4)0.042 (5)0.008 (4)0.009 (4)0.010 (4)
C130.047 (6)0.042 (4)0.046 (5)0.019 (4)0.001 (4)0.005 (4)
C140.027 (5)0.071 (6)0.038 (4)0.003 (4)0.001 (3)0.003 (4)
C150.051 (7)0.048 (4)0.043 (5)0.004 (4)0.003 (4)0.001 (4)
C160.034 (5)0.034 (4)0.036 (4)0.003 (3)0.005 (4)0.016 (3)
C210.077 (10)0.24 (2)0.090 (10)0.074 (12)0.048 (8)0.127 (13)
O310.088 (5)0.038 (3)0.036 (3)0.023 (3)0.015 (3)0.003 (2)
Geometric parameters (Å, º) top
Br1—C21.951 (9)C8—O91.481 (9)
C1—C111.486 (11)C8—H8A0.9900
C1—C51.522 (10)C8—H8B0.9900
C1—C21.582 (10)C11—C121.398 (11)
C1—H11.0000C11—C161.445 (10)
C2—C211.512 (17)C12—C131.357 (14)
C2—C31.535 (12)C12—H120.9500
C3—O311.211 (10)C13—C141.398 (13)
C3—C41.447 (11)C13—H130.9500
C4—C51.337 (11)C14—C151.377 (13)
C4—O91.369 (9)C14—H140.9500
C5—C61.491 (9)C15—C161.333 (13)
C6—C71.528 (13)C15—H150.9500
C6—H6A0.9900C16—H160.9500
C6—H6B0.9900C21—H21A0.9800
C7—C81.521 (12)C21—H21B0.9800
C7—H7A0.9900C21—H21C0.9800
C7—H7B0.9900
C11—C1—C5114.6 (6)H7A—C7—H7B108.1
C11—C1—C2115.1 (7)O9—C8—C7110.6 (7)
C5—C1—C2102.0 (6)O9—C8—H8A109.5
C11—C1—H1108.3C7—C8—H8A109.5
C5—C1—H1108.3O9—C8—H8B109.5
C2—C1—H1108.3C7—C8—H8B109.5
C21—C2—C3109.4 (9)H8A—C8—H8B108.1
C21—C2—C1116.3 (8)C4—O9—C8112.4 (6)
C3—C2—C1106.2 (6)C12—C11—C16115.0 (8)
C21—C2—Br1108.6 (10)C12—C11—C1124.7 (7)
C3—C2—Br1105.9 (6)C16—C11—C1120.2 (7)
C1—C2—Br1110.0 (5)C13—C12—C11122.9 (8)
O31—C3—C4129.1 (8)C13—C12—H12118.5
O31—C3—C2124.9 (7)C11—C12—H12118.5
C4—C3—C2106.0 (6)C12—C13—C14120.5 (8)
C5—C4—O9127.3 (7)C12—C13—H13119.7
C5—C4—C3113.3 (6)C14—C13—H13119.7
O9—C4—C3119.4 (6)C15—C14—C13117.6 (9)
C4—C5—C6121.8 (7)C15—C14—H14121.2
C4—C5—C1112.4 (6)C13—C14—H14121.2
C6—C5—C1125.5 (7)C16—C15—C14122.9 (9)
C5—C6—C7109.3 (7)C16—C15—H15118.6
C5—C6—H6A109.8C14—C15—H15118.6
C7—C6—H6A109.8C15—C16—C11121.0 (8)
C5—C6—H6B109.8C15—C16—H16119.5
C7—C6—H6B109.8C11—C16—H16119.5
H6A—C6—H6B108.3C2—C21—H21A109.5
C8—C7—C6110.6 (7)C2—C21—H21B109.5
C8—C7—H7A109.5H21A—C21—H21B109.5
C6—C7—H7A109.5C2—C21—H21C109.5
C8—C7—H7B109.5H21A—C21—H21C109.5
C6—C7—H7B109.5H21B—C21—H21C109.5
C11—C1—C2—C211.5 (13)C11—C1—C5—C661.6 (10)
C5—C1—C2—C21123.2 (12)C2—C1—C5—C6173.4 (7)
C11—C1—C2—C3123.5 (7)C4—C5—C6—C712.9 (10)
C5—C1—C2—C31.2 (8)C1—C5—C6—C7161.6 (8)
C11—C1—C2—Br1122.4 (6)C5—C6—C7—C844.3 (9)
C5—C1—C2—Br1112.9 (6)C6—C7—C8—O961.9 (10)
C21—C2—C3—O3153.9 (13)C5—C4—O9—C811.8 (11)
C1—C2—C3—O31179.9 (8)C3—C4—O9—C8170.1 (7)
Br1—C2—C3—O3163.0 (9)C7—C8—O9—C444.0 (10)
C21—C2—C3—C4126.8 (10)C5—C1—C11—C1230.5 (10)
C1—C2—C3—C40.6 (9)C2—C1—C11—C1287.3 (9)
Br1—C2—C3—C4116.3 (6)C5—C1—C11—C16150.4 (7)
O31—C3—C4—C5178.8 (8)C2—C1—C11—C1691.8 (8)
C2—C3—C4—C50.4 (9)C16—C11—C12—C131.7 (12)
O31—C3—C4—O90.4 (13)C1—C11—C12—C13177.4 (8)
C2—C3—C4—O9178.9 (6)C11—C12—C13—C140.9 (14)
O9—C4—C5—C64.4 (12)C12—C13—C14—C151.1 (13)
C3—C4—C5—C6173.9 (7)C13—C14—C15—C162.4 (14)
O9—C4—C5—C1179.6 (7)C14—C15—C16—C113.4 (14)
C3—C4—C5—C11.3 (9)C12—C11—C16—C152.9 (12)
C11—C1—C5—C4123.5 (7)C1—C11—C16—C15176.3 (8)
C2—C1—C5—C41.6 (9)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···O31i1.002.473.282 (9)138
Symmetry code: (i) x+1, y1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC15H15BrO2
Mr307.18
Crystal system, space groupOrthorhombic, P212121
Temperature (K)173
a, b, c (Å)9.2217 (11), 11.5041 (12), 12.9149 (17)
V3)1370.1 (3)
Z4
Radiation typeMo Kα
µ (mm1)2.99
Crystal size (mm)0.21 × 0.12 × 0.03
Data collection
DiffractometerSTOE IPDS II two-circle-
diffractometer
Absorption correctionMulti-scan
(MULABS; Spek, 2009; Blessing, 1995)
Tmin, Tmax0.572, 0.916
No. of measured, independent and
observed [I > 2σ(I)] reflections
11129, 2407, 1849
Rint0.078
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.082, 0.217, 1.03
No. of reflections2407
No. of parameters163
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.07, 1.13
Absolute structureFlack (1983), 1009 Friedel pairs
Absolute structure parameter0.02 (3)

Computer programs: X-AREA (Stoe & Cie, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···O31i1.002.473.282 (9)137.6
Symmetry code: (i) x+1, y1/2, z+1/2.
 

References

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