Stereochemistry of the Microbial Generation of δ-Decanolide, γ-Dodecanolide, and γ-Nonanolide from C₁₈ 13-Hydroxy, C₁₈10-Hydroxy, and C₁₉14-Hydroxy Unsaturated Fatty Acids

(S)-δ-Decanolide (4) was isolated from cultures of Cladosporium suaveolens after the microorganism was fed either (S)- or (R,S)-coriolic acid (1). Feeding (R,S)- 10-hydroxyoctadec-(8E)-enoic acid (2) to Yarrowia lipolytica produced (S)-γ-dodecanolide. When (S)-homocoriolic acid (3) was fed to C. suaveolens, γ-nonalide slightly enriched in the S enantiomer was produced. At some stage in the biodegradation of 3, an inversion of configuration, from S to fi, occurred and was accompanied by the loss of the hydrogen atom originally present on C-14, as GLC/MS analysis of the products of feeding C. suaveolens with dideuterated 10 showed.