Steroids and steroidases. VII. A unique long-range directing effect exerted by the cholestane C8H17 group on the formation of A-homosteroid ketones

Abstract

The diazomethane homologation of a broad spectrum of variously C-17-substituted steroid-3-ketones has shown that the C8H17 cholestane side chain exerts a unique influence on the direction of the ring enlargement reaction. This long-range effect is not explicable in terms of polar or conformational transmission.