rac-4,8-Divinyl­bicyclo­[3.3.1]nonane-2,6-dione

Edvinas Orentas; Ola F Wendt; Kenneth Wärnmark; Eugenijus Butkus; Carl-Johan Wallentin

doi:10.1107/S1600536809018443

. 2009 May 20;65(Pt 6):o1357. doi: 10.1107/S1600536809018443

rac-4,8-Divinylbicyclo[3.3.1]nonane-2,6-dione

Edvinas Orentas ^a, Ola F Wendt ^b, Kenneth Wärnmark ^b, Eugenijus Butkus ^a, Carl-Johan Wallentin ^b,^*

PMCID: PMC2969760 PMID: 21583208

Abstract

The title compound, C₁₃H₁₆O₂, is a chiral bicyclic structure composed of two fused cyclohexane rings possessing both boat and chair conformations. The molecules are packed in enantiopure columns which are pairwise linked forming an overall racemic solid; within the column pairs the packing is governed by weak dipole–dipole interactions stemming from stacked carbonyl functionalities (CO_centroid–CO_centroid distance = 3.290 Å).

Related literature

For related structures, see: Orentas et al. (2007 ▶); Quast et al. (1994 ▶, 1999 ▶); Wallentin et al. (2009 ▶). For a general background to non-covalent interactions, see: Desiraju & Steiner (1999 ▶); Aakeröy (1997 ▶), and references therein.

Experimental

Crystal data

C₁₃H₁₆O₂
M _r = 204.26
Orthorhombic,
a = 20.4254 (11) Å
b = 8.8913 (6) Å
c = 6.2570 (4) Å
V = 1136.32 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 K
0.3 × 0.05 × 0.03 mm

Data collection

Oxford Diffraction Xcalibur diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006 ▶) T _min = 0.827, T _max = 1.000 (expected range = 0.825–0.998)
8068 measured reflections
1363 independent reflections
811 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.110
S = 1.02
1363 reflections
136 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2006 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2000 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809018443/ng2580sup1.cif

e-65-o1357-sup1.cif^{(16.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809018443/ng2580Isup2.hkl

e-65-o1357-Isup2.hkl^{(67.3KB, hkl)}

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

Acknowledgments

Financial support from the Swedish Research Council, the Knut and Alice Wallenberg Foundation, The Swedish Foundation for Strategic Research, and the Royal Physiographic Society is gratefully acknowledged.

supplementary crystallographic information

Comment

The hydrocarbon backbone of the title compound is a common motif in many biologically active compounds and its unique molecular shape has been utilized in the construction of different types of supramolecular architectures and inclusion complexes. Diols from this category of structures has with great success been exploited within the field of crystal engineering. The title compound was obtained in the synthesis of a series of C₂ -symmetrically derivatized bicyclo[3.3.1]nonane-2,6-diones as a part of an ongoing project with the aim to study various supramolecular features of this class of compounds. The chiral bicyclic structure is composed of two merged cyclohexanes possessing both boat and chair conformations similar to the previously reported phenyl-substituted bicyclo[3.3.1]nonane-2,6-dione (Quast et al., 1999). The molecules are packed in column pairs which propagate in a unidirectional manner along the c axis. The column pairs are homochiral and generated by a two fold screw axis. The glide plane generates an over-all racemic structure comprised of parallel columns with alternating absolute stereochemistry. The formation of column pairs is governed by dipole-dipole interactions stemming from stacked carbonyl functionalities: centroid C2O1···centroid C2O1, 3.290 Å.

Experimental

A solution of LiCl in THF ( 0.5M, 12.5 mL, 6.25 mmol) was added to a round-bottom flask charged with CuCN (0.272 g, 3.04 mmol) and the mixture was stirred under argon at room temperature until all solid dissolved. The solution was cooled down to -30 °C and a solution of vinyl magnesium bromide in THF (0.7 M, 4.34 mL, 3.04 mmol) was added dropwise. The resulting dark brown mixture was warmed to -20 °C and stirred at this temperature for 30 minutes and then cooled to -78 °C. A solution of bicyclo[3.3.1]nona-3,7-diene-2,6-dione (0.15g, 1.01 mmol) (Orentas et al., 2007) and trimethylsilylchloride (0.33 g, 3.04 mmol) in THF (3 mL) was added dropwise. The reaction mixture was stirred until the temperature reached -20 °C. The reaction was quenched with 10% HCl solution (20 mL) and stirred at room temperature until the intermediate silylenol ether was hydrolyzed (monitored by TLC). The mixture was diluted with water and extracted with EtOAc (3 x 20 mL). The combined organic phase was dried over Na₂SO₄ and evaporated to dryness. The residue was purified by flash chromatography (10% ethyl acetate/petroleum ether) to afford the title compound as a coluorless solid in 70 % yield (144.4 mg). The product was recrystallised from petroleum ether to give colourless crystals suitable for X-ray diffraction analysis; m.p. 65 °C; FTIR (KBr) 1700 (C=O) cm^-1; ¹H NMR (300 MHz, CDCl₃) δ 5.83 (ddd, J₁=17.0 Hz, J₂=10.4 Hz, J₃=6.0 Hz, 1H), 5.17 (dd, J₁=10.4 Hz, J₂=1.6 Hz, 1H), 5.10 (dd, J₁=17.0 Hz,J₂=1.6 Hz, 1H), 2.93-2.83 (m, 2H), 2.62-2.53 (m, 6H), 2.19-2.14 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 211.86, 139.34, 116.01, 48.10, 39.46, 22.81; Anal. calcd for C₁₃H₁₆O₂: C, 76.44; H, 7.90. Found: C, 76.57; H, 8.02.