STEROIDS AND STEROIDASES: I. LONG-RANGE EFFECTS AND THE PREPARATION OF A-HOMOSTEROIDS

Abstract

The direction of the diazomethane ring enlargement of 17β-hydroxy-5α-androstan-3-one (I, R = OH) appears to be controlled by the long-range effect of the 17β-hydroxyl group, and proceeds with migration of the C3—C4 bond to give the A-homo-3-one III (R = OH). This is in direct contrast to the rearrangement of 5α-cholestan-3-one (I, R = C8H17), which gives the A-homoketone II (R = C8H17) as a result of C2—C3 bond migration. An analogous directing effect was not observed for the reaction of diazomethane with 17β-hydroxy-5β-androstan-3-one (VII). Oxidation of the A-homo-17β-alcohols gave the corresponding diones III (R = =O), X, and XI.