18-METHYL-19-NOR-20-KETO-PREGNANES AND PROCESS FOR PREPARING THEM

摘要

ABSTRACT OF THE DISCLOSUREAn 18-methyl-19-nor-20-keto-pregnane of the generalformula (I)which has a central depressive, anaesthatic-narcotic action, isproduced, for example, by treating a 17.beta.-acetoxy-18-methyl-19-nor17.alpha.-pregnane of the general formula (II)with an alkali metal, e.g. lithium or an alkaline earth metal inliquid annonia. In the above formulae, R1 and R2 together repre-sent an oxygen atom, or one of R1 and R2 represents a hydrogen atomand the other a hydroxyl group; R3 represents an oxygen atom or twohydrogen atoms, and the hydrogen atom in the 5-position is in the.alpha.-or .beta.-position.