GB792410A - Improvements in or relating to steroidal compounds - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:0792410/IV (b)/1> in which the 3-position is occupied either by a bivalent group convertible to keto by acid hydrolysis or by a pair of univalent groups together convertible to a single keto group by acid hydrolysis and compounds of the formula <FORM:0792410/IV (b)/2> in which the 3-position is occupied by a univalent group which is convertible to keto by acid hydrolysis. In compounds of the first formula the 3-position may be occupied by cyclic ketal groups, e.g. ethylenedioxy, ethylenedithioketal or ethylene hemithioketal or by cyclic amine groups or by non-cyclic ketal groups, e.g. dimethyl ketal or dimethyl thioketal. In compounds of the second formula the 3-position may be occupied by an enol ether group. Such compounds are obtained by treating a 1-acetaldehydo-2,4,b-dimethyl-2(b -ketopropyl) - 4 - keto - 1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydrophenanthrene appropriately substituted in the 7-position (cf. Specification 792,411) with an alkaline reagent such as potassium hydroxide. In an example 1-acetaldehydo - 2(b - ketopropyl) - 2,4b - dimethyl - 4 - keto - 7 - ethylenedioxy - 1,2,3,4,4a,4b,5,6,7,-8,10,10a-dodecahydrophenanthrene is heated with a 2.5 per cent potassium hydroxide solution to give dl-D 5,16-3-ethylenedioxy-11,20-diketo pregnadiene. The product is useful in the preparation of cortisone. It can be reduced using a Raney nickel catalyst to dl-D 5-3-ethylenedioxy - pregnene - 11,20 - dione which can be converted to cortisone by known methods. Specification 763,208 also is referred to.