PROCEDURES FOR OPTICAL DETERMINATION OF A RAZEMIC ALPHA SUBSTITUTE, HETEROZYCLICAL CARBONIC ACID UNDER ENZYME USE

摘要

Disclosed is a method for optically resolving a racemic alpha-substituted heterocyclic carboxylic acid (alpha-HCCA) by taking advantage of enantioselectivity of enzymes. alpha-HCCA is reacted with alcohol to give a racemic alpha-HCCA ester, which is then reacted with an enzyme with enantioselectivity, whereby either R-form or S-form of the racemate is hydrolyzed. Extraction with an organic solvent can obtain enantiomers of the alpha-HCCA ester. The extracted enantiomeric alpha-HCCA ester is converted to enantiomeric alpha-HCCA by catalytic hydrogenation in an organic solution or by enzymatic hydrolysis in an aqueous solution. Thus, a racemic mixture of alpha-HCCA can be optically resolved with high optical purity at high yields as well as at low cost.