cis-4-Hydroxy-D-proline methyl ester hydrochlorideMethyl (2R,4R)-4-hydroxypyrrolidine-2-carboxylate hydrochloride(2R,4R)-4-Hydroxy-2-(methoxycarbonyl)pyrrolidine hydrochloride(2R,4S)-4-Hydroxy-2-(methoxycarbonyl)pyrrolidine hydrochloridetrans-4-Hydroxy-D-proline methyl ester hydrochloride(2S,4R)-Methyl 4-hydroxypyrrolidine-2-carboxylate hydrochlorideMethyl (2R,4S)-4-hydroxypyrrolidine-2-carboxylate hydrochloride(2R,4R)-Methyl 4-hydroxypyrrolidine-2-carboxylate hydrochloride