allyl (8S,9R,10S)-5-[[1-(allyloxycarbonyl)pyrrolidin-3-yl]carbamoyl]-10-[(R)-1-hydroxyethyl]-11-oxo-1,5-diazatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate

allyl (8S,9R,10S)-5-[[Nω-(allyloxycarbonyl)guanidino]carbonyl]-10-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-11-oxo-1,5-diazatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate

allyl (8S,9R,10S)-5-[3-[[N,N'-bis(allyloxycarbonyl)amidino]amino]propionyl]-10-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-11-oxo-1,5-diazatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate

(3R,4S)-4-[(R)-1-benzyl-3-oxopiperidin-4-yl]-1-(tert-butyldimethylsilyl)-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-azetidinone