4-(2-Acetylamino-4-tert-butoxycarbonyl-butyrylamino)-4-[1-(1-{5-[1-(allyloxycarbonylmethyl-aminooxalyl)-butylcarbamoyl]-1-benzyl-2-oxo-imidazolidine-4-carbonyl}-2-methyl-propylcarbamoyl)-2-methyl-propylcarbamoyl]-butyric acid , tert-butyl ester AIDS-222895 AIDS222895