PURPOSE: Readily available optically active proline is used as an asymmetric source and an organometallic compound is subjected to conjugate addition to its N-α,β-unsaturated carboxylic acid amide derivative in the presence of a tertiary amine and the product is hydrolyzed to effect the high-yield production of the titled substance used as a starting compound for various reagents.

CONSTITUTION: An α,β-unsaturated carboxylic acid amide derivative of optically active proline or hydroxyproline of formula I (R is alkyl, aryl; R1 is H, hydroxyl) is used as an asymmetric source to undergo conjugate addition of at least one selected from organometallic compounds of formula III (X is halogen) and formula II (R" is alkyl, aryl) such as butyl lithium in the presence of a tertiary amine such as trimethylamine in an aprotonic organic solvent under anhydrous conditions, preferably at -40W0°C, then the product is hydrolyzed to give the objective compound.