(3S,4R)-1-allyloxalyl-4-[(2S,6R)-2-[(S)-(1-allyloxycarbonyl)pyrrolidin-3-ylthiomethyl]cyclohexanon-6-yl]-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]azetidin-2-one

allyl (4S,8S,9R,10S)-4-[(S)-(1-allyloxycarbonyl)pyrrolidin-2-ylmethylthiomethyl]-10-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-11-oxo-1-azatricyclo[7.2.0.03,8]undec-2-ene-2-carboxylate