C-aromatic steroids. Synthesis of 11,17ξ-dimethoxy-18-norandrosta-4,8,11,13-tetraen-3-one

Abstract

Birch reduction of 5-hydroxy-7-methoxy-1H-cyclopenta[a]naphthalen-3(2H)-one (1) afforded 3,5-dihydroxy-7-methoxy-2,3,6,9-tetrahydro-1H-cyclopenta[a] naphthalene (2a) in high yield. The latter has been transformed into the title C-aromatic steroid (7a) through steps involving methylation, hydrolysis, C-methylation, and Robinson annulation. The analogous synthesis of 11,17ξ-dimethoxygona-4,8,11,13-tetraen-3-one (7b) is also described.