Direct Conversion of S-(+)-Bulbocapnine into S-(+)-2-Hydroxy-10-methoxyaporphine

Abstract

The opening of a methylenedioxy group with simultaneous elimination of an oxygen atom during sodium in liquid ammonia reduction is a well established process in the aporphine alkaloid series¹. It has furthermore been reported that phosphate esters of phenols are deoxygenated under similar reaction conditions². The alkaloid bulbocapnine (1) contains an aromatic methylendioxy group and a phenolic hydroxy group; it thus seemed indicated to attempt the direct removal of two oxygen atoms by treating the phosphate ester 2 with an alkali metal in liquid ammonia. We now would like to give experimental details regarding this practical step which was summarized elsewhere³.