(2S,3R)-3-(tert-Butyl-dimethyl-silanyloxy)-2-methoxycarbonylmethyl-pyrrolidine-1-carboxylic acid benzyl ester
methyl (2S,3R)-(1-benzyloxycarbonyl-3-hydroxypyrrolidin-2-yl)acetate
(1S,5S)-(-)-6-aza-2-oxabicyclo[3.3.0]octan-3-one
(1S,5S)-(+)-6-aza-6-benzyloxycarbonyl-2-oxabicyclo[3.3.0]octan-3-one
(1R,5R)-(-)-6-aza-6-benzyloxycarbonyl-2-oxabicyclo[3.3.0]octan-3-one