Enantioselective synthesis of unsaturated α-hydroxy acids

Article abstract of DOI:10.1016/S0957-4166(97)00571-5

(S)- and (R)-2-Hydroxyhex-5-enoic acid and (S)- and (R)-2-hydroxyhept- 6-enoic acid were prepared in excellent yields and enantiomeric excesses (>99% ee) from the corresponding α-keto esters by the enzyme catalysed hydrolysis of the ester and reduction of the ketone in a single pot process. The enantioselective synthesis of (S)-2-hydroxypent-4-enoic acid was achieved via reaction of the reagent derived from allyl bromide and indium metal with the hydrate of 8-phenylmenthyl glyoxalate in water.