t-butyl 7β-amino-7α-formamidocephalosporanate

t-butyl 7β-amino-7α-(methylthio)cephalosporanate

t-butyl 7α-amino-7β-<(2,2,2-trichloroethoxy)carbonylamino>cephalosporanate

t-butyl 7α-(methylthio)-7β-<(2,2,2-trichloroethoxy)carbonylamino>cephalosporanate

trimethylsilyl (6R,7R)-3-(acetoxymethyl)-7-((3,5-di-tert-butyl-4-hydroxybenzylidene)amino)-7-formamido-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate