(1S,5R,8aS,8bR)-1-[(R)-1-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-5-[(E)-2-(2-ethyl-2H-pyrazol-3-ylcarbamoyl)-vinyl]-2-oxo-1,2,5,6,7,8,8a,8b-octahydro-azeto[2,1-a]isoindole-4-carboxylic acid allyl ester

allyl (4S,8S,9R,10S)-4-[(benzothiazol-2-yl)thiomethyl]-10-[(R)-1-hydroxyethyl]-11-oxo-azatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate

allyl (4S,8S,9R,10S)-4-(N,N-bis(allyloxycarbonyl)aminomethyl)-10-[(R)-1-hydroxyethyl]-11-oxo-azatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate

allyl (4S,8S,9R,10S)-4-[[1,2-bis(allyloxycarbonyl)guanidino]methyl]-10-[(R)-1-hydroxyethyl]-11-oxo-azatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate

allyl (4S,8S,9R,10S)-4-(N,N-bis(allyloxycarbonyl)aminomethyl)-10-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-11-oxo-azatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate