methyl (3R,6S,7aR)-3-(tert-butyl)-5,7-dioxo-6-phenyl-6-(pyridin-2-ylmethyl)dihydro-1H,3H-pyrrolo[1,2-c]oxazole-7a(5H)-carboxylate

methyl (3R,7aR)-3-(tert-butyl)-6-(cyclohexylmethylene)-5,7-dioxodihydro-1H,3H-pyrrolo[1,2-c]oxazole-7a(5H)-carboxylate