13c-(2-Chloro­ethoxy)-1,13c-dihydro-2,3-epoxy­dibenzo[a,kl]xanthan-1-one

Jin-Xiang Chen; Yu-Qin Wang; Shu-Guang Wu; Zhi-Hong Jiang; Zhi-Peng Chen

doi:10.1107/S1600536808030973

. 2008 Oct 4;64(Pt 11):o2069. doi: 10.1107/S1600536808030973

13c-(2-Chloroethoxy)-1,13c-dihydro-2,3-epoxydibenzo[a,kl]xanthan-1-one

Jin-Xiang Chen ^a, Yu-Qin Wang ^a, Shu-Guang Wu ^a, Zhi-Hong Jiang ^a, Zhi-Peng Chen ^a,^*

PMCID: PMC2959592 PMID: 21580935

Abstract

The title compound, C₂₂H₁₅ClO₄, containing three chiral C atoms, is an intermediate in the design of chiral alcohols. In the crystal structure, a chain structure is generated through C—H⋯O contacts and an intramolecular C—H⋯O interaction also occurs. The dihedral angle between the benzene ring and the naphthalene system is 16.5°.

Related literature

For related literature, see: Aronne et al. (2008 ▶); Sasidharan et al. (2002 ▶); Tan et al. (2001 ▶); Wang et al. (2003 ▶); Yamazaki (2008 ▶).

Experimental

Crystal data

C₂₂H₁₅ClO₄
M _r = 378.79
Orthorhombic,
a = 7.7966 (13) Å
b = 10.4468 (18) Å
c = 21.349 (4) Å
V = 1738.9 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 193 (2) K
0.30 × 0.20 × 0.10 mm

Data collection

Rigaku Mercury diffractometer
Absorption correction: multi-scan (Jacobson, 1998 ▶) T _min = 0.930, T _max = 0.966
10185 measured reflections
3416 independent reflections
2809 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.136
S = 1.06
3416 reflections
244 parameters
19 restraints
H-atom parameters constrained
Δρ_max = 0.59 e Å⁻³
Δρ_min = −0.35 e Å⁻³
Absolute structure: Flack (1983 ▶) , 1440 Friedel pairs
Flack parameter: 0.00 (11)

Data collection: CrystalClear (Rigaku/MSC, 2001 ▶); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808030973/tk2302sup1.cif

e-64-o2069-sup1.cif^{(21.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808030973/tk2302Isup2.hkl

e-64-o2069-Isup2.hkl^{(167.6KB, 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
C14—H14A⋯O2ⁱ	0.95	2.55	3.392 (4)	147
C19—H19A⋯O4	0.95	2.54	3.084 (3)	117

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by the Medical Scientific Research Foundation of Guangdong Province, China (grant No. B2006091) and the NSF of Guangdong Province, China (grant No. 7300449).

supplementary crystallographic information

Comment

Epoxides are well known as one of the most valuable building blocks used as intermediates and precursors for pharmaceuticals (Yamazaki, 2008; Aronne, et al., 2008). The title compound, (I), is a key intermediate in the preparation of chiral alcohols, which we are designing for potential use as antiviral agents. The structure of (I), Fig. 1, provides information on the potential stereoselectivity of its ring-opening reactions (Sasidharan et al., 2002; Wang et al., 2003). The molecule of (I) contains six fused rings with the three aromatic rings almost coplanar. The six-membered carbocyclic ring adopts a slightly twisted boat conformation and the pyran ring is nearly planar. The epoxy group points in the same direction as the OCH₂CH₂Cl group, having a syn relationship. In the crystal structure, molecules of (I) associate in a head-to-tail manner, parallel to the b axis, via O-H···O hydrogen bonds to form a 1D structure, Fig. 2 and Table 1.

Experimental

Compound (I) was obtained by epoxidation of 13c-(2-chloroethyloxy)-1-oxo-1,13c-dihydrodibenzo[a,kl]xanthene in methanol with aqueous hydrogen peroxide (30%) under mild reaction conditions (Tan et al., 2001). Compound (I) was the main product, isolated in a yield of 92%. Crystals suitable for X-ray analysis were obtained from the slow evaporation of an acetone solution (m.p. 527–529 K). IR (KBr disk): 3409, 2905, 2359, 1720 (s, C=O), 1454, 1267, 1097, 776, 755, 508 cm^-1. ¹H NMR (300 MHz in CDCl₃/TMS): 3.15–3.25 (m, 2H), 3.27–3.38 (m, 2H), 4.04 (d, J = 3.9 Hz, 1H), 4.34 (d, J = 3.9 Hz, 1H), 7.24–7.26 (m, 1H), 7.27 (d, J = 9.0 Hz, 1H), 7.34–7.49 (m, 4H), 7.78–7.79 (m, 1H), 7.86 (d, J = 9.0 Hz, 1H), 7.96–8.02 (m, 1H) p.p.m. FAB-MS (m/z): 299(M⁺ –OCH₂CH₂Cl).