Patent ID: 7449325

Claim:
A process for preparing an optically active β-amino acid and an optically active β-amino acid ester or N-substituted 2-homopipecolic acid and an optically active N-substituted 2-homopipecolic acid ester which comprises selectively hydrolyzing an enantiomer of a racemic mixture of an N-substituted β-amino acid alkyl ester or an N-substituted 2-homopipecolic acid ester represented by the formula (I): wherein Ar represents a substituted or unsubstituted aryl group, R 1 represents a substituted or unsubstituted alkyl group, alkenyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R 2 represents a hydrogen atom or R 1 and R 2 are joined covalently to form a C 4 saturated alkylene group, thereby forming a 6-membered ring with R 1 and R 2 and the atoms to which they are bonded, R 3 and R 4 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and R 5 represents a substituted or unsubstituted alkyl group, in the presence of a Candida antarctica lipase capable of catalyzing the hydrolysis of said enantiomer to form an optically active ((R) or (S))—N-substituted-β-amino acid or an optically active ((R) or (S))—N-substituted-2-homopipecolic acid represented by the formula (II): simultaneously to obtain an unreacted optically active ((S) or (R))—N-substituted-β-amino acid alkyl ester or an unreacted optically active ((S) or (R))—N-substituted-2-homopipecolic acid ester represented by the formula (III): provided that the ester of formula (III) has a reverse steric absolute configuration to that of the compound represented by the formula (II).