4-NITROBENZYL (R)-4-((2R,3S)-3-((R)-1-((TERT-BUTYLDIMETHYLSILYL)OXY)ETHYL)-4-OXO-2-AZETIDINYL)-3-OXOPENTANOATE
4-nitrobenzyl (r)-4-((2r,3s)-3-((r)-1-((tert-butyldimethylsilyl)oxy)ethyl)-4-oxo-2-azetidinyl)-3-oxopentanoate