tert-butyl 2-[(6R,8S)-8-methyl-4-oxo-6-[[4-(N-phenylmethoxycarbonylcarbamimidoyl)phenyl]methylcarbamoyl]-3-[phenylmethoxycarbonyl(prop-2-enyl)amino]-6,7-dihydropyrrolo[1,2-a]pyrimidin-8-yl]acetate