[(1S,2S,3R,4R)-3-Hydr­oxy-4,7,7-tri­methyl­bicyclo­[2.2.1]heptan-2-yl]methyl[(E)-3-(trimethyl­silyl)prop-2-enyl]selen­onium bromide

Hai-Yang Wang; Qiang Zhang; Yi-Zhi Li; Yuan Gui; Zhi-Zhen Huang

doi:10.1107/S1600536808016863

. 2008 Jun 7;64(Pt 7):o1245. doi: 10.1107/S1600536808016863

[(1S,2S,3R,4R)-3-Hydroxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]methyl[(E)-3-(trimethylsilyl)prop-2-enyl]selenonium bromide

Hai-Yang Wang ^a, Qiang Zhang ^a, Yi-Zhi Li ^b, Yuan Gui ^a, Zhi-Zhen Huang ^a,^*

PMCID: PMC2961745 PMID: 21202880

Abstract

The title compound, a selenonium bromide, C₁₇H₃₃OSeSi⁺·Br⁻, was obtained from the reaction of enantiomerically pure 4,7,7-trimethyl-2-methylselanylbicyclo[2.2.1]heptan-3-ol and (3-bromopropenyl)trimethylsilane in acetone. Due to the chiral bicyclic substituent, the crystal structure is not centrosymmetric and has no symmetry plane, with four chiral C atoms in the cation. The asymmetric unit contains one selenonium cation and one bromide anion. C–H⋯Br and O–H⋯Br hydrogen bonds link the ions, forming a one-dimensional R-helical chain-like supramolecular structure.

Related literature

For related literature, see: Li et al. (2005 ▶); Goodridge et al. (1988 ▶); Reich et al. (1975 ▶); Ye et al. (2002 ▶).

Experimental

Crystal data

C₁₇H₃₃OSeSi⁺·Br⁻
M _r = 440.39
Monoclinic,
a = 7.555 (2) Å
b = 10.023 (2) Å
c = 14.423 (3) Å
β = 101.29 (3)°
V = 1071.0 (4) Å³
Z = 2
Mo Kα radiation
μ = 3.67 mm⁻¹
T = 291 (2) K
0.30 × 0.26 × 0.24 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.35, T _max = 0.41
4460 measured reflections
3374 independent reflections
1732 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.102
S = 1.07
3374 reflections
170 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.74 e Å⁻³
Absolute structure: Flack (1983 ▶), 1140 Friedel pairs
Flack parameter: 0.01 (2)

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SMART; data reduction: SAINT (Bruker, 2000 ▶); 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.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808016863/im2070sup1.cif

e-64-o1245-sup1.cif^{(19.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808016863/im2070Isup2.hkl

e-64-o1245-Isup2.hkl^{(193.5KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1D⋯Br1	0.87 (8)	2.28 (8)	3.143 (5)	175 (7)
C5—H5⋯Br1ⁱ	0.98	2.88	3.827 (5)	164
C11—H11C⋯Br1ⁱⁱ	0.96	2.94	3.874 (7)	165
C12—H12B⋯Br1ⁱ	0.97	2.97	3.855 (5)	152

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

We thank the National Natural Science Foundation of China for its financial support of projects 20332050 and 20572042

supplementary crystallographic information

Comment

Recently, an efficient asymmetric synthesis of cyclopropanes via camphor-derived sulfonium ylides was reported (Ye et al., 2002). Thus, we expected that camphor-derived selenonium ylides could be used in the highly enantioselective synthesis of cyclopropanes, epoxides and aziridines. First, the camphor-derived selenide (1) was prepared from commercially available D-camphor according to a literature method (Reich et al., 1975; Goodridge et al., 1988, and Li et al., 2005). Then compound (1) was reacted with (3-bromo-propenyl)-trimethylsilane (3) to give the selenonium salt (2). We performed the X-ray crystallographic analysis of (2) in order to elucidate the conformation and configuration.

The structural analysis shows that the selenonium ion of the title compound, (2) (Fig. 1), is not centrosymmetric and has no symmetry plane, showing the four chiral C atoms, C4, C5, C6, and C7, with the R, R, S, and S configuration preserved from the enatiomerically pure starting compound (1). The asymmetric unit contains one selenonium salt cation, and one bromide ion. In the crystal packing, the Br atom plays an important role, acting as a bridge linking neighboring molecules via C–H···Br and O–H···Br hydrogen bonds (O1—H1D···Br1, C5—H5···Br1ⁱⁱ, C11—H11c···Br1ⁱ, and C12—H12B···Br1ⁱⁱ; symmetry code i: x,-1 + y,z; ii: 1 - x,-1/2 + y, -z), forming a one dimensional R-helical chains-like structure along [010] axis (Fig. 2).

Experimental

A solution of 4,7,7-trimethyl-2-methylselanyl-bicyclo[2.2.1]heptan-3-ol (1) (2.4 g, 9.7 mmol) and (3-bromo-propenyl)-trimethylsilane (3) (1.9 g, 9.7 mmol) in acetone (5 mL) was stirred at 273 K. The solid was collected and washed with ethyl ether to afford the selenonium salt (2) in 91% yield. Single crystals of (2) were obtained by slow evaporation from 10 mL of a methanolic solution containing 50 mg (2).