5a-Androstanes microbial hydroxylation

The hydroxylation of 5a-androstanes has previously been discussed on a microorganism basis, and yields of from a few percent up to 50% or better can be achieved. The work has since been extended to cover the microorganism Leptoporus flssilis with oxygenated Sa-androstanes and the microbial oxidation of A-nor- and A-homo-5a-androstanes by Cunninghamella elegans. The chemically modified ste-... 

Microbial reduction of carbonyl groups is another possible side reaction, with a 3-keto group seemingly most susceptible to this reaction, but again the nature of the substrate and microorganism can have a major effect on the extent of this side reaction. In the hydroxylation of 5a-androstan-3-one (66) the results shown in Table 4 were obtained. ... 

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