Stereoselective Epoxidation of 4-Bromo-1-Butene and 3-Butene-1-Ol with Three Alkene-Utilizing Bacteria

Stereoselective epoxidation of 4-bromo-1-butene and 3-butene-1-ol was carried out with three alkene-utilizing bacteria: Mycobacterium LI, Mycobacterium E3 and Nocardia IP1. The enantiomeric compositions of 4-bromo-1,2-epoxybutane and 4-hydroxy-1,2-epoxybutane were determined by optical rotation and checked by 1H NMR using a chiral shift reagent and by 19F NMR after reaction with the Mosher reagent. The presence of a bromine atom or a hydroxyl group induced some variations in the stereochemical course of the microbial epoxidation. The epoxides were produced predominantly in the 2R-form but their enantiomeric composition depended on both the microorganism used and on the substrate studied.