Synonyms: D-Proline,4-hydroxy-, methyl ester, hydrochloride, (4R)- (9CI); D-Proline, 4-hydroxy-, methylester, hydrochloride, cis-; (2R,4R)-4-Hydroxypyrrolidine-2-carboxylic acidmethyl ester hydrochloride; 4-(R)-Hydroxypyrrolidine-2-(R)-carboxylic acidmethyl ester hydrochloride