. "((S)-2-Methyl-1-{(1S,3aR,6aS)-1-[1-((S)-1-phenyl-ethylaminooxalyl)-butylcarbamoyl]-hexahydro-cyclopenta[c]pyrrole-2-carbonyl}-propyl)-carbamic acid isopropyl ester" . "4A" . . . . . . .