Structure of Equilenin at 100 K: an estrone-related steroid

Frampton, C. S. and MacNicol, D. D. (2017) Structure of Equilenin at 100 K: an estrone-related steroid. Acta Crystallographica. Section E: Crystallographic Communications, 73(Pt 8), pp. 1223-1226. (doi: 10.1107/S2056989017010532) (PMID:28932441) (PMCID:PMC5598853)

Abstract

The structure of the estrone-related steroid, Equilenin, C18H18O2 (systematic name 3-hy-droxy-13-methyl-11,12,13,14,15,16-hexa-hydro-cyclo-penta-[a]phen-anthren-17-one), has been determined at 100 K. The crystals are ortho-rhom-bic, P212121, and the absolute structure of the mol-ecule in the crystal has been determined by resonant scattering [Flack parameter = -0.05 (4)]. The C atoms of the A and B rings are almost coplanar, with an r.m.s. deviation from planarity of 0.0104 Å. The C ring has a sofa conformation, while the D ring has an envelope conformation with the methine C atom as the flap. The keto O atom and the methyl group are translated 0.78 and 0.79 Å, respectively, from the equivalent positions on 17β-estrone. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains parallel to the c-axis direction.

• Item Type: Articles
• Keywords: Equilenin, Equilin, conformation, crystal structure, estrone, hydrogen bonding, steroid.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacNicol, Dr David
• Authors: Frampton, C. S., and MacNicol, D. D.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Acta Crystallographica. Section E: Crystallographic Communications
• Publisher: International Union of Crystallography
• ISSN: 2056-9890
• ISSN (Online): 2056-9890
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Acta Crystallographica. Section E: Crystallographic Communications 73(Pt 8): 1223-1226
• Publisher Policy: Reproduced in accordance with the publisher copyright policy