Microbiological transformations. Part 4. Microbiological transformations of 5α-androstan-17-ones and of 17a-aza-D-homo-5α-androstan-17-ones with the fungus Cunninghamella elegans

Abstract

The microbiological transformation of 5α-androstan-17-one, and the 3β-acetoxy- and 3α-hydroxy-derivatives, by Cunninghamella elegans is dominated by 1β,7-dihydroxylation or 7-monohydroxylation. 3α-Acetoxy-5α-androstan-17-one undergoes predominant 6β,11β-dihydroxylation. 17a-Aza-D-homo-5α-androstan-17-one and the 3α-acetoxy-derivative undergo predominant monohydroxylation at 6β or 7α, in contrast to the 3β-acetoxy-derivative which, although undergoing similar monohydroxylation, gives good yields of 9α-monohydroxylated products.