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

摘要

An 18-methyl-19-nor-20-keto-pregnane of the general formula (I) which has a central depressive, anaesthatic-narcotic action, is produced, for example, by treating a 17.beta.-acetoxy-18-methyl-19-nor 17.alpha.-pregnane of the general formula (II) with an alkali metal, e.g. lithium or an alkaline earth metal in liquid annonia. In the above formulae, R1 and R2 together represent an oxygen atom, or one of R1 and R2 represents a hydrogen atom and the other a hydroxyl group; R3 represents an oxygen atom or two hydrogen atoms, and the hydrogen atom in the 5-position is in the .alpha.-or .beta.-position.