Acid-catalysed decomposition of β,γ-unsaturated diazo-ketones preparation of 4,4-dimethyl-D-nor-steroidal systems from pimaradiene and sandaracopimaradiene precursors

Abstract

4,4-Dimethyl-17-nor-5α,13α-androst-8-en-16-one (9) and 3β-acetoxy-4,4-dimethyl-17-nor-5α-androst-8-en-16-one (19) have been prepared by the acid-catalysed intramolecular cyclization of 16-diazopimar-8(14)-en-15-one (7) and 3β-acetoxy-16-diazoisopimar-7-en-15-one (16) prepared from pimara-8(14),15-diene (5) and isopimara-7,15-dien-3β-ol acetate (10), respectively.