Synonyms: Pentanoicacid, 5-[(2,5-dioxo-1-pyrrolidinyl)oxy]-4-[[(9H-fluoren-9-ylmethoxy)carbonyl]amino]-5-oxo-,1,1-dimethylethyl ester, (4S)- (9CI); Pentanoic acid,5-[(2,5-dioxo-1-pyrrolidinyl)oxy]-4-[[(9H-fluoren-9-ylmethoxy)carbonyl]amino]-5-oxo-,1,1-dimethylethyl ester, (S)-