GB897732A - Cyclopentanophenanthrene derivatives - Google Patents

Abstract

6-Alkyl-steroids of the general formula <FORM:0897732/IV (b)/1> p wherein R is alkyl of 1 to 3 carbon atoms, X is a keto or b -hydroxy group, and Y is a double bond or saturated linkage between C1 and C2, are prepared from the corresponding 3,20-bisethylene ketal of D 4-pregnen-17a -o1,3,20-dione having an 11-keto or 11b -hydroxy group by reaction with a peracid, treatment of the resulting 5a ,6a -epoxide with an alkyl magnesium bromide to form a 5a -o1-6b -alkyl compound which is then treated with an acid and then a base to hydrolyse the ketal groups, dehydrate to form a 4 : 5 double bond and to invert the 6b -alkyl group. The 11b -hydroxyl group in the starting material may be formed by reduction of an 11-keto group with lithium aluminium hydride, and the D 1-double bond may be introduced by treatment with selenium dioxide. Treatment of the resulting 6a -lower alkyl pregnene and pregnadiene compounds with iodine in the presence of calcium oxide yields the corresponding 21-iodo compounds, which with potassium acetate give the corresponding 21-hydroxy compounds. Detailed examples illustrate the preparation of 6a -methyl cortisone acetate, 6a -methylprednisone and its acetate, and 6a -methylprednisolone and its acetate. Specificatio 776,858 is referred to. Reference has been directed by the Comptroller to Specifications 863,778 and 864,380.