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

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

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