NMR study of conformation and configuration in C-20-substituted 5β,14β-pregnanes, 5β-pregn-14-enes and 21-nor-5β,14β-pregnanes

✍ Scribed by Kirk Marat; J. F. Templeton; Yangzhi Ling

• Book ID: 102950362
• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 540 KB
• Volume: 31
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260310106

✦ Synopsis

Abstract

Coupling constants and nuclear Overhauser effect measurements were used to establish the C‐20 configuration and the conformation about the C‐17C‐20 bond in a series of sixteen C‐20‐substituted 5β,14β‐pregn‐14‐enes. In the 14β‐pregnane series the conformation of the C‐17 side‐chain is variable, whereas in the pregnenes the side‐chain adopts a conformation in which H‐17 is anti to H‐20. The C‐17 side‐chain conformation of two 21‐nor‐5β,14β‐pregnanes was also determined. In the 21‐nor compounds a C‐20 hydroxyl adopts a conformation anti to H‐17, while a C‐20 nitro group is anti to C‐13.