(3S)-4-ethoxy-4-oxo-3-(phenylmethoxycarbonylamino)butanoate

N-苄氧羰基-D-天冬氨酸

N-CBZ-L-天冬氨酸

4-[(1-甲氧基-1-氧代-3-苯基丙烷-2-基)氨基]-4-氧代-3-(苯基甲氧羰基氨基)丁酸

benzyl N-(2,5-dioxooxolan-3-yl)carbamate