(2R,3R)-2-[(4-Chloro­phen­yl)hydroxy­meth­yl]cyclo­penta­none

Dongsheng Deng; Ping Liu; Weijun Fu; Baoming Ji

doi:10.1107/S160053680804261X

. 2008 Dec 20;65(Pt 1):o164–o165. doi: 10.1107/S160053680804261X

(2R,3R)-2-[(4-Chlorophenyl)hydroxymethyl]cyclopentanone

Dongsheng Deng ^a, Ping Liu ^b, Weijun Fu ^a, Baoming Ji ^a,^*

PMCID: PMC2968076 PMID: 21581621

Abstract

The title compound, C₁₂H₁₃ClO₂, was prepared by the direct asymmetric intermolecular aldol reaction of cyclopentanone and 4-chlorobenzaldehyde catalysed by l-tryptophan in water. The absolute molecular structure was determined to be a racemic twin with 91% (2R,3R) isomer and 9% of the (2S,3S) form. In the crystal structure, the molecules are connected into a one-dimensional chain along the a axis through the formation of intermolecular O—H⋯O hydrogen bonds. Further, non-conventional C—H⋯O and C—H⋯π contacts are observed in the structure, which consolidate the crystal packing.

Related literature

For the structure of 2-[hydroxy(4-nitrophenyl)methyl]-4-methylcyclohexanone, see: Li (2007 ▶). For a structure with C—H⋯O hydrogen bonds, see: Nangia (2002 ▶). For a database study of C—H⋯π interactions in the conformation of peptides, see: Umezawa et al. (1999 ▶). For direct intermolecular aldol reactions catalysed by acyclic amino acids, see: Córdova et al. (2006 ▶); Deng & Cai (2007 ▶). For asymmetric direct aldol reaction assisted by water and a proline-derived tetrazole catalyst, see: Torii et al. (2004 ▶). For the development of direct catalytic asymmetric aldol, Mannich, Michael and Diels–Alder reactions, see: Notz et al. (2004 ▶).

Experimental

Crystal data

C₁₂H₁₃ClO₂
M _r = 224.67
Orthorhombic,
a = 5.7401 (1) Å
b = 10.4549 (2) Å
c = 18.2135 (3) Å
V = 1093.03 (3) Å³
Z = 4
Cu Kα radiation
μ = 2.90 mm⁻¹
T = 150 (2) K
0.43 × 0.31 × 0.25 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.336, T _max = 0.484
3762 measured reflections
1936 independent reflections
1865 reflections with I > 2σ(I)
R _int = 0.040

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.168
S = 1.14
1936 reflections
146 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.52 e Å⁻³
Absolute structure: Flack (1983 ▶), 572 Friedel pairs
Flack parameter: 0.09 (3)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); 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 and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680804261X/si2143sup1.cif

e-65-0o164-sup1.cif^{(16.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680804261X/si2143Isup2.hkl

e-65-0o164-Isup2.hkl^{(95.3KB, 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—H1⋯O2ⁱ	0.92 (7)	1.89 (7)	2.793 (4)	165 (7)
C10—H10A⋯O2ⁱⁱ	0.99	2.53	3.328 (5)	138
C5—H5A⋯Cg2ⁱⁱⁱ	0.95	2.96	3.818 (4)	150

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg2 is the centroid of the C1–C5,C12 ring.

Acknowledgments

This work was supported by the Doctoral Foundation and Cultivatable Foundation (2008-PYJJ-011) of Luoyang Normal University.

supplementary crystallographic information

Comment

The direct asymmetric aldol reaction is one of the most important C—C bond-forming reactions (Notz et al., 2004.). It is not surprising that a large number of catalysts and methods have been developed to achieve efficient adducts with high diastereo- and enantioselectivities (Córdova et al. 2006; Torii et al. 2004.). Our primary results demonstrating that acyclic amino acids could catalyze the direct stereoseletive aldol reaction in water micelles (Deng & Cai, 2007). In this contribution, as an extension to our previous studies, we report the synthesis and crystal structure of the title compound.

In the title compound (Fig. 1.), the bond lengths and angles are within ranges as reported by Li (2007). The structural analysis reveals that the absolute molecular structure was a (2R, 3R)- isomer. The most striking feature of the title compound is the interesting arrangement of the title molecules, which connect each other to form a one-dimension chain along the a axis by intermolecular O—H···O hydrogen bonds (Fig. 2). Furthermore, the weak non-conventional intermolecular C—H···π contact is observed, in which C5—H5A is donor and the chlorophenyl ring Cg2 (C1, C2, C3, C4, C12, C5) is π acceptor (Umezawa et al., 1999). This contact, with additional intermolecular C—H···O interactions (Nangia et al. 2002), further consolidate the crystal packing. Details of hydrogen bonds are given in Table 1.

Experimental

4-chlorobenzaldehyde (71 mm g, 0.5 mmol) and cyclopentanone (0.5 ml) was added to a solution of L-tryptophan (30.6 mg, 0.15 mmol) and pure water (0.5 ml) at room temperature. The mixture was stirred, monitored by TLC. The mixture was quenched with a saturated aqueous NaHCO₃ solution and extracted by ethyl acetate (3× ml). The resulting solvent was removed in vacuo to yield the crude product. Purification by silica gel chromatography using 100 ~200 mesh ZCX II eluted by hexane-ethyl acetate (3:1, v/v) gave the yellow solid (70 mg, yield 63%). The crystalline compound was obtained through the slow volatilization of ethyl acetate containing the title compound.