PURPOSE: To provide new (2S, 1'S, 2'S)-α-(2-labeled-2-carboxycylopropyl)glycine which is a selective agonist of metabolism-regulation type glutamic acid receptor and its new intermediate.

CONSTITUTION: A (2S, 1'S, 2'S)-α-(2-labeled-2-carboxyclopropyl)glycine of formula I (R2 is deuterium atom or tritium atom), e.g. (4S, 1'S, 2'S)-N-t- butoxycarbonyl-2,2-dimethyl-4-(2-deuterio-2-methoxycarbonylcyclopropyl)glycine. The compound of formula 1 can be provided by reducing the ester group of a compound of formula 3 (Boc is t-butoxycarbonyl; R1 is a lower alkyl) to an alcohol, oxidizing the alcohol compound to obtain a compound of formula 4, treating with an alkali in a deuterated or tritiated solvent, oxidizing and esterifying the resultant compound of formula 5 and converting the obtained new intermediate compound of formula 2 through a compound of formula 6.