Reduction ofketones

Ionic liquid [bmimJPFg can be used as a solvent in yeast reduction [21]. The reduction ofketones with immobilized baker s yeast (alginate) in a 100 10 2 [bmimjPFfi ionic liquid water MeOH mix affords chiral alcohols (Figure 8.28). 

Reductions ofketones -alcohol dehydrogenase-catalyzed pNZYMES IN ORGANIC SYNTHESIS] (Vol 9)... 

Istuno and coworkers reported an enantioselective reduction ofketones using a flow reactor, in which polymer-supported amino alcohol was fixed (Scheme 7.7). As butyl phenyl ketone and borane (1.2 equiv.) in THF were separately and continuously pumped into the reactor (overflow type), the desired alcohol was obtained in 84% yield with 83-93% ee. With analogous batch reactions, ee values were 81%-92%. Thus, with this reaction, both the flow and batch procedures gave similar results [41]. 

Grdger, H., Chamouleau, F., Orologas, N Rollmarm, C., Drauz, K., Hummel, W Weckbecker, A., and May, O. (2006) Enantioselective reduction ofketones with designer cells at high substrate concentrations highly efircient access to functionalized optically active alcohols. Angew. Chem., Int. Ed., 45, 5677-5681. 

Scheme12.28 Stereoselective reduction ofketone 54 catalyzed by WHOA TESADH.

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