Biotransformations with baker's yeast: pH effects on diastereoselectivity during α-hydroxy-β-ketoester reductions and carbon-carbon bond cleavages

Article abstract of DOI:10.1016/S0957-4166(97)00232-2

Baker's yeast mediated reduction of α-substituted-β-ketoesters lead to reduction of the carbonyl group with high enantiospecificity and diastereoselectivity at low pH (4.0-5.0, e.e. >99%, d.e. >90%) but cleavage of the C-C bond is observed at higher pH >8.0). Similar carbon-carbon bond cleavages are observed in the reactions of α-acetamido-β-ketoesters and acetamidocinnamic acid.