Chemical-microbiological semisynthesis of enantio-Ambrox derivatives

Article abstract of DOI:10.1016/S0040-4020(99)00474-3

enantio-3-Hydroxyambrox derivatives were obtained through combined chemical and microbiological methods from ent-12-dioxo-13-epi-manoyl oxides. Regioselective and stereoselective reduction of the carbonyl group at C-3 of ent-3,12-dioxo-13-epi-manoyl oxide was carried out with Baker's yeast. Regioselective acetylation of ent-3,12-dihydroxy-13-epi-manoyl oxide was accomplished with Candida cylindracea lipase or Novozym 435 and vinyl acetate. Microbial biotransformation of ent-3 β-acetoxy-12-oxo-13-epi- manoyl oxide with Neetria ochroleuca yielded new ent-1β-hydroxy- and ent- 7β-hydroxy derivatives. Baeyer-Villiger oxidation at C-12 was observed in the biotransformation with baker's yeast and G. roseun to obtain norambreinolide lactones which were converted in to enantio-Ambrox derivatives.