Chemo- and Stereodivergent Preparation of Terminal Epoxides and Bromohydrins through One-Pot Biocatalysed Reactions: Access to Enantiopure Five- and Six-Membered N-Heterocycles

Different enantiopure terminal epoxides or bromohydrins have chemoselectively been synthesised in one-pot starting from the corresponding α-bromoketones through alcohol dehydrogenase (ADH)-catalysed processes adding an organic co-solvent and tuning appropriately the medium pH and the temperature. Thus, at neutral pH enantiopure bromohydrins were obtained while using basic conditions (pH 9.5-10) epoxides were isolated as the main product. Furthermore, by simple selection of the biocatalyst, chemoand stereodivergent transformations were achieved to obtain, e.g. enantiopure prolinol or piperidin-3-ol.