Synthesis of dehydro-oogoniol, a female-activating hormone of Achlya: the progesterone route.

The structure of dehydro-oogoniol (3 beta,11 alpha,15 beta,29-tetrahydroxystigmasta-5,24(28)(E)-dien-7-one), a female-activating hormone of the water mold Achlya, has been confirmed by synthesis. The starting material was progesterone, which was converted to the 11 alpha, 15 beta-dihydroxy derivative by microbiological hydroxylation with Aspergillus giganteus (ATCC 10059). The side chain was constructed in a stepwise manner by means of Wittig and Horner-Emmons reactions, and the C-7 ketone was then introduced by allylic oxidation.

Conversion of 15 alpha-hydroxy-11-oxo-progesterone to 3 beta, 11 alpha, 15 beta-trihydroxy-5-pregnen-20-one.

3 beta, 11 alpha, 15 beta-Trihydroxy-5-pregnen-20-one, an intermediate required for the synthesis of the oogoniols, has been prepared from 15 alpha-hydroxy-11-oxoprogesterone in an overall yield of 16%. The three isomers (at C-11, C-15) of the pregnene were also prepared.