Microbial Baeyer-Villiger Oxidation of Bicyclo[4.3.0]ketones by Two Recombinant E. coli Strains. A Novel Access to Indole Alkaloids

Recombinant Escherichia coli overexpressing Pseudomonas sp. NCIMB 9872 cyclopentanone monooxygenase (CPMO; E.C. 1.14.13.16) and Acinetobacter sp. NCIMB 9871 cyclohexanone monooxygenase (CHMO; E.C. 1.14.13.22) have been utilized in whole-cell biotransformations of prochiral bicyclo[4.3.0]ketones. The lactones produced in a biocatalytic Baeyer-Villiger oxidation represent key intermediates for the synthesis of several indole alkaloids. The two over-expression systems demonstrated a tendency for the formation of opposite enantiomers with CPMO giving (+)-lactones in good yields and excellent enantiomeric excess.