2 STEROIDAL EPIMERS, -ALPHA)-PREGNA-20-YNO[3,4-C][1,2,5]OXADIAZOL-17-OL (THE 5-BETA-EPIMER) AND -ALPHA)-PREGNA-20-YNO[3,4-C][1,2,5]OXADIAZOL-17-OL (THE 5-ALPHA-EPIMER)

Authors
LISGARTEN DR PALMER RA MAES D LISGARTEN J WYNS L
Citation
Dr. Lisgarten et al., 2 STEROIDAL EPIMERS, -ALPHA)-PREGNA-20-YNO[3,4-C][1,2,5]OXADIAZOL-17-OL (THE 5-BETA-EPIMER) AND -ALPHA)-PREGNA-20-YNO[3,4-C][1,2,5]OXADIAZOL-17-OL (THE 5-ALPHA-EPIMER), Acta crystallographica. Section C, Crystal structure communications, 51, 1995, pp. 666-670
Citations number
13
Categorie Soggetti
Crystallography
Journal title
Acta crystallographica. Section C, Crystal structure communications → ACNP
ISSN journal
01082701
Volume
51
Year of publication
1995
Part
4
Pages
666 - 670
Database
ISI
SICI code
0108-2701(1995)51:<666:2SE->2.0.ZU;2-#
Abstract
The crystal and molecular structures of the steroidal oxadiazoles (5 b eta,17 alpha)-pregna-20-yno[3,4-c][1,2,5]oxadiazol-17-ol (the 5 beta-e pimer) and (5 alpha,l7 alpha)-pregna-20-yno[3,4-c][1,2,5]oxadiazol-17- ol (the 5 alpha-epimer), C21H28N2O2, have been determined. In both str uctures rings A are similar, having conformations intermediate between a strained sofa, a half-chair and an envelope. Rings B and C are also similar, adopting chair conformations. In the 5 beta-epimer, ring D h as a 13 beta-envelope conformation, while in the 5 alpha-epimer, ring D has an envelope/intermediate half-chair conformation.