The Resolution of RS‐Mandelic Acid

Abstract Racemic mandelic acid was resolved through R(‐)‐mandelic acid salt with L‐phenylalanine methyl ester in ethanol; the antipode S(+)‐mandelic acid was then recovered from the mother liquid. Both were prepared in high yield and in highly optical purity. Carboxypeptidase A was also used in the separation of S(+)‐mandelic acid via selective hydrolysis of hippuryl‐RS‐mandelic acid. Comparison of the two methods was discussed.