17-Spiromethylene steroids.

摘要

The invention relates to a steroid derivative which steroidal skeleton is bound at carbon atom 17 to a spiromethylene ring of the formula: <CHEM> wherein Ra and Rb are independently selected from the group consisting of hydrogen, methyl, and halogen; m is 1 or 2; and the asterisk denotes carbon atom 2 of the spiromethylene ring which is carbon atom 17 (or carbon atom 17 alpha of a homosteroid skeleton) of the steroid. The steroids have progestational or antiprogestational activity.