4-amino-5-methyl-3-triisopropylsilanyloxy-hexanoic acid 1-[1-(2-{[1-(2-tert-butoxycarbonylamino-2-carboxy-1-methyl-ethoxycarbonyl)-2-(4-methoxy-phenyl)-ethyl]-methyl-carbamoyl}-pyrrolidine-1-carbonyl)-3-methyl-butylcarbamoyl]-2-methyl-propyl ester