| 摘要 |
DELTA 15-Steroids of the formula <IMAGE> wherein R1 is a hydrogen atom, trialkylsilyl or acyl; R2 is ethynyl, chloroethynyl or propinyl; and X is an oxygen atom, <IMAGE> or NOR4 wherein R3 is a hydrogen atom or acyl and R4 is a hydrogen atom, acyl, alkyl or tetrahydropyranyl, possess progestational and ovulation and nidation inhibiting activities. |
