(1S,2R,5S,6R,7R,7aR)-6,7-dibenzyloxy-5-tert-butyldiphenylsilyloxymethyl-1,2-dihydroxypyrrolizidin-3-one

(1R,2S,5S,6R,7R,7aR)-6,7-dibenzyloxy-5-tert-butyldiphenylsilyloxymethyl-1,2-dihydroxypyrrolizidin-3-one

(2R,3R,4R,5R)-3,4-dibenzyloxy-N-benzyloxycarbonyl-2'-O-tert-butyldiphenylsilyl-2,5-bis(hydroxymethyl)pyrrolidine

(2S,3R,4R,5R)-3,4-dibenzyloxy-N-benzyloxycarbonyl-2'-O-tert-butyldiphenylsilyl-2,5-bis(hydroxymethyl)pyrrolidine

methyl (E)-3-[(2'R,3'R,4'R,5'S)-3',4'-dibenzyloxy-N-benzyloxycarbonyl-5'-tert-butyldiphenylsilyloxymethylpyrrolidin-2'-yl]propenoate