allyl (2S,4S)-2-((2-((N,N-dimethylsulfamoyl)amino)ethyl)carbamoyl)-4-(tritylthio)pyrrolidine-1-carboxylate

(2S,4S)-2-{[2-(allyloxycarbonylamino)ethyl]carbamoyl}-4-tritylthio-1-(allyloxycarbonyl)pyrrolidine

(2S,4S)-4-Mercapto-2-[2-(3-methyl-thioureido)-ethylcarbamoyl]-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-2-(2-Methanesulfonylamino-ethylcarbamoyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

allyl (2S,4S)-2-((2-((N,N-dimethylsulfamoyl)amino)ethyl)carbamoyl)-4-mercaptopyrrolidine-1-carboxylate