Hydrolysis of several alpha-alkyl-alpha-aryloxyacetic acid methyl esters and of alpha-methyl-alpha-(n-propyl)-alpha-(p-chlorophenoxy)acetic acid methyl ester were performed in the presence of Candida cylindrarea lipase. The alpha-alkyl-alpha-aryloxyacetic acid methyl esters and alpha-methyl-alpha-(n-propyl)-alpha-(p-chlorophenoxy)acetic acid methyl ester were incubated in buffer phosphate (pH 7-8). The reaction mixture, containing the unreacted ester and corresponding acid, showed enantiomeric excesses (ee) up to 81%. The extent of conversion was quite low for the alpha-methyl-alpha-(n-propyl)-alpha-(p-chlorophenoxy) acid methyl ester, the corresponding acid was obtained with ee > 98%
