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

Key indicators: single-crystal X-ray study; T = 296 K; mean (C-C) = 0.002 Å; R factor = 0.044; wR factor = 0.128; data-to-parameter ratio = 19.7.In the title compound, C 32 H 37 NO 3 , the central dihydropyridine ring adopts a nearly planar flattened-boat conformation, whereas both cyclohexenone rings adopt half-chair conformations. The mean and maximum deviations from the mean plane of the dihydropyridine ring are 0.1252 (9) and 0.188 (1) Å , respectively. The 4-ethoxyphenyl and phenyl rings form dihedral angles of 75.20 (4) and 82.14 (5) with the dihydropyridine mean plane, respectively. Related literature

In the title compound, C24H26O4, the central 4H-pyran ring adopts a flattened boat conformation, with the mean and maximum deviations of the ring being 0.0582 (6) and 0.1012 (3) Å, respectively. The two cyclohexenone rings on opposite sides of the pyran ring each adopt an envelope conformation; the C atom bearing a dimethyl substituent is the flap atom in each case. The mean planes of the pyran ring and the substituent benzene ring subtend a dihedral angle of 86.45 (2)°. In the crystal, molecules are linked into inversion dimers via pairs of C—H...O hydrogen bonds.

In the title compound, C21H23N3O7, the pyrimidine­dione ring adopts a screw-boat conformation, whereas the cyclo­hexenone ring adopts an envelope conformation, with the C atom bearing the methyl groups as the flap atom. The dihedral angle between the mean planes of the pyrimidine­dione and cyclo­hexenone rings is 58.78 (2)°. The pyrimidine­dione and cyclo­hexenone rings form dihedral angles of 59.94 (3) and 54.73 (2)°, respectively, with the 4-nitro­phenyl ring. Relatively strong intra­molecular O—H⋯O hydrogen bonds are observed. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming a chain along the c-axis direction.