328086-57-3
(2S,4S)-2-tert-butoxycarbonylamino-4-cyanomethyl-pentadioic acid dimethyl ester
→
328086-60-8
(2S)-2-(tert-butoxycarbonylamino)-3-[(3'S)-2'-oxo-3'-pyrrolidinyl]propanoic acid methy ester