methyl (9R,11E,14S)-14-{[(tert-butoxy)carbonyl]amino}-5-[(methoxycarbonyl)amino]-16-{[2-(trimethylsilyl)ethoxy]methyl}-8,16,18-triazatricyclo[13.2.1.02,7]octadeca-1(17),2,4,6,11,15(18)-hexaene-9-carboxylate