(1S,4S,5S,6R)-6-(4-Bromo­phen­yl)-5-nitro­bicyclo­[2.2.2]octan-2-one

Aibao Xia; Jie Tang; Yifeng Wang; Junrong Jiang; Shuping Luo

doi:10.1107/S1600536809001275

. 2009 Jan 17;65(Pt 2):o326. doi: 10.1107/S1600536809001275

(1S,4S,5S,6R)-6-(4-Bromophenyl)-5-nitrobicyclo[2.2.2]octan-2-one

Aibao Xia ^a, Jie Tang ^a, Yifeng Wang ^a, Junrong Jiang ^a, Shuping Luo ^a,^*

PMCID: PMC2968281 PMID: 21581931

Abstract

The title compound, C₁₄H₁₄BrNO₃, contains a bicyclic ring system with four chiral centers. The absolute structure was established by the Flack method.

Related literature

For the asymmetric Diels-Alder reaction, which in principle allows the formation of four contiguous asymmetric centers, see: Anrendt et al. (2000 ▶); Northrup & MacMillan (2002 ▶); Xu et al. (2007 ▶); Xu et al. (2008 ▶).

Experimental

Crystal data

C₁₄H₁₄BrNO₃
M _r = 324.17
Orthorhombic,
a = 6.4675 (8) Å
b = 10.0007 (13) Å
c = 20.108 (3) Å
V = 1300.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 3.16 mm⁻¹
T = 293 (2) K
0.38 × 0.33 × 0.27 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.758, T _max = 1.000 (expected range = 0.325–0.428)
7669 measured reflections
2823 independent reflections
2201 reflections with I > 2σ(I)
R _int = 0.057

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.084
S = 0.90
2823 reflections
173 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.53 e Å⁻³
Absolute structure: Flack (1983 ▶), 1161 Friedel pairs
Flack parameter: 0.024 (12)

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809001275/pv2129sup1.cif

e-65-0o326-sup1.cif^{(18.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809001275/pv2129Isup2.hkl

e-65-0o326-Isup2.hkl^{(138.6KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

We acknowledge the help of Professor Jie Sun of Shanghai Institute of Organic Chemistry.

supplementary crystallographic information

Comment

There has been growing interest in the study of asymmetric Diels-Alder reaction because it allows in principle the formation of four contiguous asymmetric centers (Anrendt et al., 2000; Northrup & MacMillan, 2002; Xu et al., 2007, 2008). Consequently, we have synthesized a series of Diels-Alder products in our laboratory and the crystal structure and absolute configuration of one of these, the title compound, (I), is reported in this article.

In the title compound (Fig. 1), the nitryl and the 4-bromophenyl groups lie on different sides of the plane defined by C3/C4/C5 atoms with O2—N1—C4—C5 and N1—C4—C5—C9 torsion angles of 141.4 (4) and 92.5 (5)°, respectively. The C5—H5 bond and 4-bromophenyl group are almost coplanar with H5—C5—C9—C10 torsion angle of -2.3°. The structure is devoid of any classical hydrogen bonding and the molecules of (I) are separated by normal van der Waal's forces (Fig. 2).

Experimental

A THF (1.0 ml) solution of trans-nitrostyrene (0.75 mmol) and cyclohex-2-enone (1.0 mmol) in the presence of (S)-1-methyl-2-(pyrrolidin-2-ylmethylthio)-1H-imidazole (0.15 mmol) as amine catalyst and benzoic acid (0.15 mmol) as additive at room temperature was subjected to vigorous stirring. After completion of the reaction, the mixture was washed with water (appoximately 300 ml) and extracted with ethyl acetate. The solvent was removed under reduced pressure and the residue was purified by silica gel column chromatography (eluent: petroleum ether-ethoxyethane). Single crystals were obtained by slow evaporation of an ethyl acetate solution.