Nα-(tert-butoxycarbonyl)-L-phenylalanine-N-pyrrolidinamide
tert-butyl N-(2-oxo-2-pyrrolidin-1-yl-ethyl)carbamate
benzyl N-<(1S)-2-methyl-1-(1-pyrrolidinylcarbonyl)propyl>carbamate
(S)-benzyl 2-(pyrrolidine-1-carbonyl)pyrrolidine-1-carboxylate
1-(2-benzyloxycarbonylamino-1-oxo-ethyl)-pyrrolidine