Microbiological hydroxylation. Part XVII. C-19 hydroxylation of 17-oxo-5α-androstanes and 17-oxo-3α,5-cyclo-5α-androstanes by the fungus Calonectria decora

Abstract

The sequence of microbiological reactions involved in the 19-hydroxylation of 5α-androstan-17-one has been established. When a solution of 5α-androstan-17-one in dimethyl sulphoxide is incubated with Calonectria decora, the initial 1β,6α-dihydroxylation is followed by oxidation of the 1β-hydroxy-group and then by hydroxylation at C-19 to give 6α,19-dihydroxy-5α-androstane-1,17-dione in 36% yield. This compound is readily transformed (by chemical methods) into 5α,10β-estrane-1,6,17-trione.

C-19 hydroxylation occurs also with certain substituted 17-oxo-5α-androstanes and 17-oxo-3α,5-cyclo-5α-androstanes.