3-(tert-butyl-dimethyl-silanyloxy)-2-{2-[(5-(tert-butyl-dimethyl-silanyloxy)-2-{3-methyl-2-[3-methyl-2-(2,2,2-trichloro-ethoxycarbonylamino)-butyryloxy]-butyryl}-hexahydro-pyridazine-3-carbonyl)-amino]-4-methyl-pentanoylamino}-butyric acid