Patent ID: 7846917

Claim:
An 18-Methyl-15β,16β-methylene-19-nor-20-spirox-4-en-3-one of formula I in which Z is an oxygen atom, two hydrogen atoms, a group ═NOR or ═NNHSO 2 R, R is a hydrogen atom or a straight- or branched-chain alkyl group having 1 to 4 carbon atoms, R 4 is a hydrogen atom, a halogen atom or a trifluoromethyl group, and R 6 and/or R 7 may have α or β configuration, and R 6 and R 7 are independently of one another a hydrogen atom or a straight- or branched-chain alkyl group having 1 to 4 carbon atoms or a straight- or branched-chain alkenyl group having 2 to 4 carbon atoms or a saturated cycloalkyl group having 3 to 5 carbon atoms or together are a methylene group or a double bond.