In the title compound, C24H29BrO6, the dihedral angle between the cyclo­hexenone mean planes is 57.63 (2)° while the dihedral angles between the benzene ring and the cyclo­hexenone mean planes are 58.42 (2) and 69.08 (3)°. The two cyclo­hexenone rings both show an envelope conformation, with the C atom bearing two methyl groups as the flap atom in each ring. Two intra­molecular O—H⋯O hydrogen bonds occur. In the crystal, molecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers.

In the title compound, C25H30O6, the two fused cyclo­hexa­none rings have envelope conformations, whereas the central pyran ring is roughly planar [mximum deviation = 0.045 (2) Å]. The pyran and benzene rings are almost perpendicular to each other, making a dihedral angle of 86.32 (2)°. In the crystal, molecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers.

In the acridinedione moiety of the title compound, C32H37NO4, the central di­hydro­pyridine ring adopts a flattened-boat conformation, with the N atom and the methine C atom displaced from the mean plane of the other four atoms by 0.0513 (14) and 0.1828 (18) Å, respectively. The two cyclo­hexenone rings adopt envelope conformations, with the tetra­subsituted C atoms as the flap atoms. The 3,4-di­meth­oxy­­benzene and benzyl rings are almost normal to the di­hydro­pyridine mean plane, with dihedral angles of 89.47 (9) and 82.90 (11)°, respectively. In the crystal, mol­ecules are linked via a pair of C—H⋯O hydrogen bonds, forming inversion dimers, which are, in turn, linked by C—H⋯O hydrogen bonds, forming slabs lying parallel to (001).

In the title compound, C25H32O5, the two cyclo­hexenone rings have envelope conformations with the C atom bearing two methyl groups as the flap atom in each ring. Relatively strong intra­molecular O—H⋯O hydrogen bonds are observed.

Key indicators: single-crystal X-ray study; T = 296 K; mean (C-C) = 0.002 Å; R factor = 0.052; wR factor = 0.159; data-to-parameter ratio = 25.4.In the title compound, C 23 H 24 N 2 O 7 , the central 4H-pyran ring adopts a flattened boat conformation, whereas both cyclohexenone rings adopt envelope conformations, the C atom bearing the dimethyl substituent being the flap atom in each case. The mean and maximum deviation of the pyran ring are 0.0379 (4) and 0.0605 (3) Å . The mean plane of the pyran ring and the dinitrobenzene ring make a dihedral angle of 85.88 (2) . Related literature