16 alpha -Alkyl steroids, their preparation, and pharmaceutical preparations thereof

摘要

16 alpha -Alkyl steroids of the formula <IMAGE> wherein R1 is hydrogen or methyl, R2 is hydrogen, alkyl, acyl, or glycosyl R3 is hydrogen or a substituted or unsubstituted, saturated or unsaturated lower hydrocarbon residue, and R4 is methyl, ethyl or propyl, exhibit strong progestational activity and a very low androgenic activity.