Investigations on the ring contraction step in the biosynthesis of A-nor-stanols by the marine sponge Axinella verrucosa

Abstract

The conversion of cholesterol into 3β-hydroxymethyl-A-nor-5α-cholestane by the sponge Axinella verrucosa involves the loss of 3α- and 4β-hydrogen atoms; the sponge also converts cholesterol into cholest-4-en-3-one and this conversion proceeds with loss of the 4β-hydrogen atom.