Regioselective Enzymatic Preparation of Hemisuccinates of Polyhydroxylated Steroids

Abstract
3,17β-Estradiol (1) was regioselectively acylated with succinic anhydride at the 17β-hydroxyl by the action of subtilisin Carlsberg in organic solvents. 5α-Androstane-3β,7β-diol (2), 5α-pregnane-3β,20β-diol (3) and 3α, 12α-dihydroxy-5β-cholanoic acid methyl ester (4) were acylated at the 3-hydroxyl by Chromobacterium viscosum lipase, by Candida cylindracea lipase and subtilisin. With 2 and 3 subtilisin showed with succinic anhydride a regioselectivity opposite to that previously found with the acylating agent trifluoroethyl butanoate (Riva and Klibanov, 1988)