Research Article: A second monoclinic polymorph of 3β-chloro­cholest-5-ene

Date Published: June 01, 2010

Publisher: International Union of Crystallography

Author(s): Mohd. Shaheen Khan, Othman Sulaiman, Issam Ahmed Mohamed, Chin Sing Yeap, Hoong-Kun Fun.


The title compound, C27H45Cl, is a second monoclinic polymorph which crystallizes in the space group P21 with four crystallographically independent mol­ecules in the asymmetric unit. The structure was previously reported [Bernal et al. (1940 ▶). Philos. Trans. R. Soc. London Ser. B, 239, 135–182; Vani & Vijayan (1979 ▶). Mol. Cryst. Liq. Cryst.51, 253–264], also in the space group P21, but with two unique mol­ecules in the asymmetric unit. As in the previously reported structures, rings A and C in the mol­ecule adopt chair conformations with half-chair conformations for rings B and D. The ring junctions B–C and C–D are trans, whereas the junction A–B is quasi-trans. In the crystal structure, mol­ecules are arranged in a head-to-tail fashion along a and are stacked along the b axis.

Partial Text

For general background to steroid compounds, see: Doorenbos & Wu (1968 ▶); Green et al. (1978 ▶); Clinton & Manso (1961 ▶); Rajnikant et al. (2006 ▶). For the structures of the other polymorphs of the title compound, see: Bernal et al. (1940 ▶); Vani & Vijayan (1979 ▶). For ring conformations, see: Cremer & Pople (1975 ▶). For the melting point of the title compound, see: Baker & Squire (1948 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer, (1986 ▶).




0 0 vote
Article Rating
Notify of
Inline Feedbacks
View all comments