4-benzylsulfanyl-2-[tert-butoxycarbonylmethyl-(4-methoxy-benzenesulfonyl)-amino]-butyric acid methyl ester

4-benzylsulfanyl-2-[[(dicyclohexylmethyl-carbamoyl)-methyl]-(4-methoxy-benzenesulfonyl)-amino]-N-trityloxy-butyramide

4-benzylsulfanyl-2-((4-methoxy-benzenesulfonyl)-{[(pyridin-3-ylmethyl)-carbamoyl]-methyl}-amino)-N-trityloxy-butyramide

4-benzylsulfanyl-2-{(4-methoxy-benzenesulfonyl)-[(4-methoxy-benzylcarbamoyl)-methyl]-amino}-butyric acid

4-benzylsulfanyl-2-((4-methoxy-benzenesulfonyl)-{[(pyridin-3-ylmethyl)-carbamoyl]methyl}-amino)-butyric acid methyl ester

4-benzylsulfanyl-2-[cyclohexylcarbamoylmethyl-(4-methoxy-benzenesulfonyl)-amino]-butyric acid

2-[[(benzhydryl-carbamoyl)-methyl]-(4-methoxy-benzenesulfonyl)-amino]-4-benzylsulfanyl-N-trityloxy-butyramide