GB945158A - New steroid compounds and processes for their formation - Google Patents

Abstract

The invention comprises pregna-3,20-dione compounds having the formula: <FORM:0945158/C2/1> wherein R and R1 both represent cyclic ketal groupings, R2 represents a hydroxyl group in the a -orientation and a hydrogen atom, the oxygen atom =O of a keto group or a hydroxy group and a methyl group, or alternatively R1 is the oxygen atom =O of a keto group and R and R2 remain as before or alternatively both R and R1 represent the oxygen atom =O of a keto group and R2 is as before; when R represents the cyclic ketal group then a double bond exists between the 5- and 6-positions but when R represents the oxygen atom =O then the double bond lies between the 4- and 5-positions; and processes for the preparation thereof by ketalising 12a -hydroxy-progesterone at the 3- and 20-positions, oxidising the ketal thus obtained to produce the corresponding 3,20-dicyclic ketal of pregn-5-en-12-one, reacting this compound with a Grignard reagent to form the corresponding 3,20-dicyclic ketal of 12 #x-hydroxy12 #x-methyl-pregn-5-ene, which compound may be hydrolysed to liberate one or both of the protected ketone groups by acid hydrolysis. Ketalisation may be effected with ethylene glycol in the presence of p-toluene-sulphonic acid, oxidation with chromic acid and the Grignard reaction with methyl magnesium bromide.