An improved stereospecific total synthesis of an aromatic c-ring testosterone analogue

Abstract

An improved stereospecific synthesis of 17β-hydroxy-11-methoxy-18-norandrosta-4,8,11,13-tetraen-3-one (12) from 5-hydroxy-7-methoxy-1H-benz[e]inden-3(2H)-one (1) is described. Higher yields were achieved in the Birch reduction step using 3,5-dihydroxy-7-methoxy-2,3-dihydro-1H-benz[e]inden-3-ol as the starting material. An interesting replacement reaction of the benzylic hydroxy by an alkoxy-group is described.