Microbiological hydroxylation of steroids. Part X. 1β,11α-Dihydroxylation of 3β-hydroxy-5α-pregnan-20-one and the hydroxylation of other 20-oxo-5α-pregnanes with the fungus Aspergillus ochraceus

Abstract

Hydroxylation of 3β-hydroxy-5α-pregnan-20-one with Aspergillus ochraceus, in shake-flasks or using 10g batch fermentation, gives 1β,3β,11α-trihydroxy-5α-pregnan-20-one as the main product (ca. 50% yield); this trihydroxy-ketone is readily converted into 5α-pregn-1-ene-3,11,20-trione. With some other 20-oxo-5α-pregnanes containing a second oxygen group, the initial 11α-hydroxylation is followed by a variety of processes which lead to mixtures of products.