Synonyms: L-Proline,4-hydroxy-, phenylmethyl ester, hydrochloride, (4R)- (9CI); L-Proline,4-hydroxy-, phenylmethyl ester, hydrochloride, trans-; 4-Hydroxy-L-prolinebenzyl ester hydrochloride; Benzyl L-hydroxyprolinate hydrochloride;trans-4-Hydroxy-L-proline benzyl ester hydrochloride