Methyl N-acetyl phenylserinates (1, 2), methyl N-acetyl nitrophenylserinates (3, 4), and methyl N-benzoyl threoninates (5, 6) were resolved conveniently into the enantiomers with high optical purities by enzymatic hydrolysis in the presence of α-chymotrypsin, subtilisin, or bromelain. The threo and erythro forms were treated separately and the latter form was usually more reactive. Chymotrypsin and subtilisin are highly specific for the enantiomer ...
