Synthesis of 14β-Pregnanes. II. Nuclear Magnetic Resonance Sepctroscopic Evidence for the Conformation of the C-Rings in C/D cis-11β, 12β-Oxygenated Pregnanes

Abstract

The synthesis of C/D cis 11β, 12β-oxygenated pregnane derivatives from 3β, 12β-diacetoxy-5α, 25D-spirostan-11-one (II) vis dienone (V) is described. Nuclear magnetic resonance studies indicated the possible conformation of the C-ring in C/D-cis pregnane is not a boat but a chair form.