4-nitrobenzyl (4R,5S,6S)-6-((R)-1-((tert-butyldimethylsilyl)oxy)ethyl)-3-(ethylthio)-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate

正丁胺

N-甲基-4-硝基苄胺

1-(重氮基甲基)-4-硝基苯

p-nitrobenzyl hydroxy-(2-iodomethyl-4-oxoazetidin-1-yl)acetate