Enantioselective hydrolysis of esters of secondary alcohols using lyophilized Bakers' yeast

Determination of the absolute configuration of (-)-(3R)-O-beta-D-glucopyranosyloxy-5-phenylpentanoic acid from Polygonum salicifolium

The absolute configuration of the title compound has been determined after its enzymatic hydrolysis to 3-hydroxy-5-phenylpentanoic acid, esterification, and identification of the enantiomerically pure methyl (3R)-hydroxy-5-phenylpentanoate by HPLC on Chiralcel(R)OD-H. For reasons of inconsistent literature data, enantioselective reductions of methyl 3-oxo-5-phenylpentanoate have been reinspected and the stereochemical outcome unequivocally confirmed by both chiroptical and HPLC retention data.

Strategies for the chemoenzymatic preparation of optically active 1-alkyn-3-ols

A series of (R)- and (S)-1-alkyn-3-ols, chiral building units for the synthesis of leukotrienes and pheromones, were prepared via enantioselective hydrolysis of their racemic esters. While the majority of biocatalysts employed (lipases, fermenting or freeze-dried microorganisms) failed in discriminating between enantiomers, lyophilized cells of baker's yeast (Saccharomyces cerevisiae Hansen) gave (S)-1-alkyn-3-ols and their corresponding (R)-esters with greater than 90% e.e.