(2S,4R)-4-benzoyloxy-2-mesyloxymethyl-1-(p-nitrobenzyloxycarbonyl)pyrrolidine

(6R,8S)-8-acetylthio-2,2-diethyl-4-oxo-1,3-diazabicyclo[4.3.0]nonane

(6S,8R)-8-benzoyloxy-2,2-diethyl-4-oxo-1,3-diazabicyclo[4.3.0]nonane