ENZYMATIC-SYNTHESIS OF CHIRAL C4 BUILDING-BLOCKS FROM MESO-TARTARIC ACID

The optically active C4 building blocks 1, 2, and 4 are ultimately available from maleic acid on a 10-mmol scale. Compounds 1 and 2 are obtained from the dimethyl ester of O-methylated meso-tartaric acid, 3 (R1 = R2 = CH3), by saponification of either the pro-R or pro-S ester group with porcine liver esterase (as porcine liver-acetone powder) or the lipase from Candida cylindricea, respectively. Compound 4 is obtained from a reaction product of 3 by enzymatic acylation. The chemical yields and ee values in these reactions are all greater than 90%.