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Racemic 2-chlorophenyl glycine has been resolved to obtain (S)-α-amino-(2-chlorophenyl)acetic acid with >99% enantiomeric purity via enantioselective hydrolysis of its N-phenylacetyl derivative with penicillin G acylase immobilized on Eupergit C. The resolution can be conveniently performed in water at substrate concentration of 10% in 5 h with an enzyme:substrate ratio of 1:5 (w/w), and the enzyme can be recycled >25 times without any loss of activity. The unwanted (R)-enantiomer can be easily racemized for recycling.

A crude extract of Mung bean meal ( Phaseolus radiatus ) possessing epoxide hydrolase activity immobilized in gelatin gel (gelozyme) is employed in the stereoselective epoxide ring opening of glycidate esters. Thus, ethyl trans -(±)-3-phenyl glycidate 1a and methyl trans -(±)-3-(4-methoxyphenyl) glycidate 1b gave (2 S ,3 R )-glycidate esters (ee >99% and 45% yield) with gelatin immobilized enzyme in diisopropyl ether. The corresponding (2 R ,3 S )-enantiomer of 1a was hydrolyzed by an epoxide hydrolase to predominantly give the anti -product, ethyl (2 R ,3 R )-2,3-dihydroxy-3-phenylpropanoate, with a diastereomeric excess of 78% and ee 94% (40%). A small amount (5%) of racemic syn -product was also obtained as a result of the spontaneous hydrolysis. In the case of 1b , the hydrolysis product was racemic due to high reactivity of the glycidate toward water.