(2R,3S,4R)-N-benzyl-3,4-bis(benzyloxy)-2-<(1S)-1-hydroxy-3-butenyl>pyrrolidine
(3S,4S,5R)-1-benzyl-5-benzyloxymethyl-3,4-dihydroxy-2-pyrrolidinone
(2R,3S,4R)-N-benzyl-3,4-(isopropylidenedioxy)-2-(trityloxymethyl)-pyrrolidine
(2S,3S,4S)-2,3-isopropylidenedioxy-4-trityloxymethyl-4-butanolide
(2S,3S,4S)-2,3-dihydroxy-4-trityloxymethyl-4-butanolide