Abstract
Optically pure D-tert.-leucine was obtained by the enzymatic hydrolysis of (±)-N-acetyl-tert. leucine chloroethyl ester after about 50% conversion, this being catalyzed by a protease from Bacillus licheniformis (Alcalase®), and subsequent acidic saponification of the recovered ester. Among the methyl, ethyl, octyl, chloroethyl and trichloroethyl esters, the chloroethyl ester exhibited the highest rate of hydrolysis.