Enantioselective reductions of ketones using baker's yeast

Baker's yeast has been successful employed to reduce carbonyl compounds carrying appropriated substituents at distances under the electronic influence of the keto group. High yields and enantiomeric excess (ee) were obtained with 1,2-alkanedione, 1,2-alkanedione (2-O-methyloxime) and 1,3-alkanedione. Potential chiral building blocks were obtained and applied for stereoselective synthesis of valuable compounds. Evidence for a free radical chain process was obtained with baker's yeast reduction of a-iodoacetophenone using radical inhibitors