Dieth­yl 2,6-dibenz­yl-4,8-dioxotetra­hydro-2,3a,4a,6,7a,8a-hexa­aza­cyclo­penta­[def]fluorene-8b,8c-dicarboxyl­ate

The mol­ecule of the title compound, C₂₈H₃₂N₆O₆, shows normal geometrical parameters. The crystal packing is stabilized by a C—H...O inter­action.

2,6-Dibenzyl-8b,8c-diphenyl-2,3a,4a,6,7a,8a-hexa­azaperhydro­cyclo­penta­[def]fluorene-4,8-dione

The mol­ecule of the title compound, C₃₄H₃₂N₆O₂, exhibits normal geometric parameters. The two terminal phenyl rings make a dihedral angle of 69.24 (2)° with each other. The crystal packing is stabilized mainly by van der Waals inter­actions.

Diethyl 2,6-bis­(2-hydroxy­ethyl)-4,8-dioxo-1,2,5,6-tetra­hydro­hydro-2,3a,4a,6,7a,8a-hexa­azacyclo­penta[def]fluorene-8b,8c-dicarboxyl­ate

In the title glycoluril derivative, C₁₈H₂₈N₆O₈, the N-C_carbon­yl bond distances are much shorter than the other N-C bond distances in the same five-membered ring, indicating electron delocalization within the nearly planar ring. Both six-membered rings display chair conformations.

Diethyl 2,6-dicyclo­hexyl-4,8-dioxo-2,2,3,6,7-tetra­hydro-1H,5H-2,3a,4a,6,7a,8a-hexa­azacyclo­penta­[def]fluorene-8b,8c-dicarboxyl­ate

In the title compound, C₂₆H₄₀N₆O₆, the five-membered rings adopt envelope conformations and the six-membered rings are in chair conformations. The crystal packing is stabilized by C—H...O hydrogen bonds.

Dimethyl 2,6-di-tert-butyl-4,8-dioxo-1,2,5,6-tetra­hydro-2,3a,4a,6,7a,8a-hexa­azacyclo­penta[def]fluorene-8b,8c-dicarboxyl­ate

The title compound, C₂₀H₃₂N₆O₆, is a glycoluril derivative. The mol­ecule is built up from four fused rings, namely two nearly planar imidazole five-membered rings and two non-planar triazine six-membered rings. In the five-membered imidazole rings, the N—C_carbon­yl bond distances are much shorter than the other N—C distances, indicating π–π conjugation within the nearly planar ring. Both six-membered rings display chair conformations.