ethyl (1S,5R,6S)-7-(tert-butoxycarbonyl)-5-(methanesulfonyloxy)-7-azabicyclo[4.1.0]hept-2-ene-3-carboxylate

(2R,3S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-3-((R)-3-(ethoxycarbonyl)-1-hydroxybut-3-en-1-yl)aziridine-1-carboxylate

(1S,3S,4R,5R)-ethyl 4-azido-3-(tert-butoxycarbonylamino)-5-hydroxycyclohexanecarboxylate