Enviar rexistro por email: 3,3,6,6-Tetra­methyl-9-[6-(3,3,6,6-tetra­methyl-1,8-dioxo-2,3,4,5,6,7,8,9-octa­hydro-1H-xanthen-9-yl)pyridin-2-yl]-2,3,4,5,6,7,8,9-octa­hydro-1H-xanthene-1,8-dione