p. 62 - 65
(2021/11/26)(S)-2-{[1-((S)-2-Acetylsulfanyl-3-methyl-butyrylamino)-cyclopentanecarbonyl]-amino}-3-(4-hydroxy-phenyl)-propionic acid butyl ester
(S)-3-(4-Hydroxy-phenyl)-2-{[1-((S)-2-mercapto-3-methyl-butyrylamino)-cyclopentanecarbonyl]-amino}-propionic acid butyl ester
(S)-2-[(1-tert-Butoxycarbonylamino-cyclopentanecarbonyl)-amino]-3-(4-hydroxy-phenyl)-propionic acid butyl ester