On the synthesis of cardioactive steroid glycosides. On cardioactive steroids. XI

Abstract

A stereoselective β-glycosidation of digitoxose and digitoxigenin involving a 1–3 participation of a urethane group is described. The conversion of digitoxin (10) to its furyl derivative 11 and the rcoxidation of 11 to digitoxin and isodigitoxin (12), respectively, in high yield is reported for the first time. This is of fundamental importance for the use of the new glycosidation method in the total synthesis of digitoxin and its analogues.