Enzymatic Synthesis of Enantiomerically Pure Alcohols in Two-Phase Systems

Enantiomerically pure small alcohols are useful as buidling blocks for pharmaceuticals and fine chemicals. These alcohols can be synthesized from prochiral ketones using chemical and biocatalysis. A greater enantiomeric excess (ee) can be achieved through biocatalysis, specifically with the enzyme alcohol dehydrogenase (ADH). Using ADH, two-phase reaction systems containing an aqueous reactive phase and an organic reservoir phase provide superior reaction conditions compared to one-phase systems. The presented research examines the synthesis of (R)-2-butanol in both batchwise and continuous two-phase biocatalyzed systems. The greatest batchwise ee achieved was 96% while gaining a 69% conversion. Employing a continuous reaction system, the greatest ee was 93% with a conversion of 68%.