Effect of additives on the bioreduction of 2-chloro-1-phenyl-2-propen-1-one by baker’s yeast

The reduction of 2-chloro-1-phenyl-2-propen-1-one (2) by baker’s yeast (Saccharomyces cerevisiae) was performed under various reaction conditions, such as the addition of allyl alcohol, sucrose, thermal pre-treatment of the cells and use of a citrate buffer at pH 4.0. 2-Chloro-1-phenyl-1-propan-1-one (3) was produced after 2 h in a poor enantiomeric excess (ee) while after a longer period of fermentation, the compounds 1R,2R- and 1R,2S-2-chloro-1-phenylpropan-1-ol (4) were obtained at 80–90 and 28–63% ee.