(2S,4S)-2-[(2-azidoethyl)carbamoyl]-4-tritylthio-1-(allyloxycarbonyl)pyrrolidine

(2S,4S)-2-{[(5,6-Dihydro-4H-pyrimidin-1-yl)-imino-methyl]-carbamoyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-2-{[(Thiomorpholine-4-carbothioyl)-amino]-methyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-2-{[(Thiomorpholine-4-carbonyl)-amino]-methyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

(2R,4S)-2-{2-[(Z)-Hydroxyimino]-2-[(4-hydroxy-piperidine-1-carbonyl)-amino]-ethyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester