Exploring the potential of some yeast strains in the stereoselective synthesis of aldol reaction products and its reduced 1,3-dialcohol derivatives

The behavior of two yeast strains has been studied under different conditions. Both microorganims catalyzed the aldol reaction between activated aldehydes and acetone when a large amount of the latter was present in the reaction medium producing, with moderate stereoselectivity, the aldol product with the R configuration. No reduction of any of the products present in the medium was detected. On the other hand, the carbonyl group of the racemic aldol was reduced to produce chiral 1,3-dialcohol derivatives when water was employed as the only solvent. In this case, the resolution of the racemic starting material was also possible with one of the biocatalysts, and the aldol was recovered with the S configuration. A complementary enantioselectivity was shown by both microorganisms in the generation of the new stereogenic center, which allowed access to 3 of the 4 possible diastereomeric diols with high enantiomerical purity.