(4S,5S)-1-benzyloxycarbonyl-5-benzyl-4-hydroxy-2-oxopyrrolidine

(5S)-5-benzyl-4-hydroxy-1-t-butoxycarbonylpyrrol-2(5H)-one

(3S,4R,5S)-5-Benzyl-3,4-bis-benzyloxy-1-(4-methoxy-benzyl)-pyrrolidin-2-one

(3S,4R,5S)-5-Benzyl-3,4-bis-benzyloxy-pyrrolidin-2-one

(2S,3R,4S)-2-Benzyl-3,4-bis-benzyloxy-5-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester