Microbiological hydroxylation. Part XVI. Incubation of derivatives (mainly acetals) of 5α-androstane ketones with the fungi Calonectria decora, Aspergillus ochraceus, and Rhizopus nigricans

Abstract

Acetals and enol ethers derived from oxoandrostanes are less reactive than the parent ketones towards the title fungi. None of the derivatives is hydroxylated by Rhizopus nigricans, and only one by Aspergillus ochraceus. With Calonectria decora the acetals generally give patterns of hydroxylation similar to, but less specific than, those of the corresponding ketones. 16,16-Ethylenedioxy-5α-androstane is exceptional in that its hydroxylation with Calonectria decora to a 6α,12β-dihydroxy-product is more efficient than the 6α,11α-dihydroxylation of 5α-androstan-16-one.