(3R,5R)-1-(tert-butoxycarbonyl)-3-(tert-butyldimethylsiloxy)methyl-5-benzyloxycarbonyl-pyrrolidin-2-one

(2R,4S)-4-Hydroxymethyl-pyrrolidine-1,2-dicarboxylic acid 2-benzyl ester 1-tert-butyl ester

(S)-2-[(S)-2-(9H-Fluoren-9-ylmethoxycarbonylamino)-2-methyl-butyrylamino]-3-phenyl-propionic acid benzyl ester

(S)-2-[(S)-2-(9H-Fluoren-9-ylmethoxycarbonylamino)-2-methyl-butyrylamino]-3-phenyl-propionic acid

(2R,4S)-1-(tert-butoxycarbonyl)-2-benzyloxycarbonyl-4-methylpyrrolidine