ENZYMATIC RESOLUTION OF CHIRAL 2-HYDROXY CARBOXYLIC-ACIDS BY ENANTIOSELECTIVE OXIDATION WITH MOLECULAR-OXYGEN CATALYZED BY THE GLYCOLATE OXIDASE FROM SPINACH (SPINACIA-OLERACEA)

The enzymatic oxidation of a variety of saturated and unsaturated alip hatic derivatives of racemic 2-hydroxy acids 1 to their 2-oxo acids 2 with molecular oxygen catalyzed by the glycolate oxidase from spinach (Spinacia oleracea) was shown to proceed highly enantioselectively. Th us, the glycolate oxidase-catalyzed kinetic resolution provides a conv enient biocatalytic method for the preparation of enantiomerically pur e (R)-2-hydroxy acids. The absolute configuration of tbe (R)-2-hydroxy acid Ib was assigned by comparison of the measured optical rotation v alue with that of the literature data and by application of the excito n-coupled circular dichroism method (ECCD) on its bichromophoric 2-nap hthoate 9-methylanthryl derivative 3b. These results establish the ECC D method as a convenient microscale chirooptic tool for the configurat ional assignment of 2-hydroxy acids.