Kinetic resolution of aliphatic acyclic β-hydroxyketones by recombinant whole-cell Baeyer–Villiger monooxygenases—Formation of enantiocomplementary regioisomeric esters

A set of various linear aliphatic β-hydroxyketones was investigated as substrates in the enzymatic kinetic and regioselective Baeyer–Villiger oxidation catalyzed by 12 Baeyer–Villiger monooxygenases from different bacterial origin. Excellent enantioselectivities (E >100) could be observed with 4-hydroxy-2-ketones. After acyl migration, the ester undergoes hydrolysis followed by the formation of optically active 1,2-diols. Furthermore, resolution of 5-hydroxy-3-ketones gave access to the ‘abnormal’ esters, which broadens applicability of these enzymes in organic chemistry. Additionally, it was noticed, that several substrates were converted by different enzymes in an enantiocomplementary way and with high optical purities.

Graphical abstractKinetic resolution of linear aliphatic β-substituted ketones with engineered Escherichiacoli cells expressing BVMOs of different bacterial origin is reported. Regioselectivity as well as enantioselectivity of the biotransformation are examined in detail.Figure optionsDownload full-size imageDownload as PowerPoint slide