Total Syntheses of Some 7-Methyl Substituted' Estrogens

Within the last ten years many of the steroidal hormones have been totally synthesized.t-P A French firm, Roussel, has even started to manufacture most of the steroidal hormones, used in chemical therapy, by total synthesis.I ,2 So far nothing has been reported about the total syntheses of 7-methyl substituted steroids. While studying the effect of the 7-methyl group on a certain biological activityl4-16 several 7-methyl substituted steroids have been prepared by partial synthesis'Y'" with rather poor yields. For this purpose first ofall a double bond must be introduced to the steroid molecule at S-C. The resulting unsaturated molecule should then be oxidized to a 7-keto-~5 steroid. Finally the unsaturated ketone, thus obtained, when reacted with methyl magnesium iodide leads to a 7-oxo methylene steroid which could be hydrogenated with palladium oxide in glacial acetic acid-acetic anhydride mixture.