Nonenzymatic Biocatalysts

Bakers s yeast is the most widely employed biocatalyst for asymmetric ketone reductions [43]. A group at Roussel Uclaf described an industrial application of bakers yeast mediated ketone reduction for the synthesis of trimegestone [44], a progestomimetic compound for the treatment of postmenopausal diseases. The key step of the nine-step synthesis is a chemo-, regio- and stereoselective bakers yeast reduction of the triketone 5 (Scheme 4.9). This transformation could not be performed efficiently using nonenzymatic methods. 

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