Process to produce 19-nor-10beta-carboxylic acids by fungal oxidation of 6-substituted-delta6-pregnanes

A process for the production of a 19-nor-10β-carboxylic acid of Formula II

• 6
• wherein:
• R1 is selected from the group consisting of H, OH, R—C(O)O—, —CH2OCH3, CH3CH(OR)O—;
• R is a C1-C8 alkyl group;
• R2 is selected from H, F, Cl, Br, and CH3—;
• R3, is H, or CH2═;
• R4 is —CH2OH or —CH3,
• by fungal oxidation of a 6-substituted-Δ6-pregnane of Formula I
• 7
• wherein
• R1 is selected from the group consisting of H, OH, R—C(O)O—, —CH2OCH3, CH3CH(OR)O—;
• R is a C1-C8 alkyl group;
• R2 is selected from H, F, Cl, Br, and CH3—;
• R3, is H, or CH2═;
• R4 is —CH2OH or —CH3,
• R5 is —CHO, —CH2OH or CH3
• comprising:
• contacting a 6-substituted-Δ6-pregnane of Formula I with a bioconversion medium containing a species of the genus Nigrospora capable of oxidizing the 19 carbon of a 6-substituted-Δ6-pregnane of Formula I.