(2R,4R)-4-hydroxy-1,2-pyrrolidinedicarboxylic acid dimethyl ester

(4R)-4-乙酰氧基-L-脯氨酸

L-羟基脯氨酸

(1R,4R)-5-乙酰基-2-氧杂-5-氮杂双环[2.2.1]庚烷-3-酮

(2R,4R,1'S)-1-(1'-phenylethyl)-4-hydroxy-proline methyl ester