Crystal structure, Hirshfeld surface and frontier mol-ecular orbital analysis of 10-benzyl-9-(4-hydroxy-3-meth-oxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,6,7,9,10-hexa-hydro-acridine-1,8(2H,5H)-dione.

In the fused ring system of the title mol-ecule, C31H35NO4, the conformation of the central di-hydro-pyridine ring is inter-mediate between boat and envelope with the N and the opposite C atoms lying out of the basal plane. The conformations of terminal rings are close to envelope, with the atoms substituted by two methyl groups as the flaps. In the crystal, the mol-ecules are linked by O-H⋯O hydrogen bonds into helical chains. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (63.2%), O⋯H/H⋯O (20.1%) and C⋯H/H⋯C (14.4%) contacts. Quantum chemical calculations of the frontier mol-ecular orbitals were carried out to characterize the chemical reactivity of the title compound.

Crystal structure, Hirshfeld surface and frontier mol-ecular orbital analysis of 9-(3-bromo-4-hy-droxy-5-meth-oxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-1H-xanthene-1,8(2H)-dione.

In the fused ring system of the title compound, C24H27BrO5, the mean plane and maximum deviations of the central pyran ring are 0.0384 (2) and 0.0733 (2) Å, respectively. The cyclo-hexenone rings both adopt envelope conformations with the tetra-substituted C atoms as flap atoms, whereas the central pyran ring adopts a flattened boat conformation. The central pyran and phenyl substituent rings are almost perpendicular to each other, making a dihedral angle of 89.71 (2)°. In the crystal, pairs of mol-ecules are linked via O-H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(20) ring motif. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (50.6%), O⋯H/H⋯O (22.9%) and C⋯H/H⋯C (11.1%) contacts. Quantum chemical calculations for the frontier mol-ecular orbitals were undertaken to determine the chemical reactivity of the title compound.

Crystal structure, Hirshfeld surface and frontier mol-ecular orbital analysis of 10-benzyl-9-(3-eth-oxy-4-hy-droxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,6,7,9,10-hexa-hydro-acridine-1,8(2H,5H)-dione.

In the fused ring system of the title compound, C32H37NO4, the central di-hydro-pyridine ring adopts a flattened boat conformation, the mean and maximum deviations of the di-hydro-pyridine ring being 0.1429 (2) and 0.2621 (2) Å, respectively. The two cyclo-hexenone rings adopt envelope conformations with the tetra-substituted C atoms as flap atoms. The benzene and phenyl rings form dihedral angles of 85.81 (2) and 88.90 (2)°, respectively, with the mean plane of the di-hydro-pyridine ring. In the crystal, mol-ecules are linked via an O-H⋯O hydrogen bond, forming a helical chain along the b-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (65.2%), O⋯H/H⋯O (18.8%) and C⋯H/H⋯C (13.9%) contacts. Quantum chemical calculations for the frontier mol-ecular orbitals were undertake to determine the chemical reactivity of the title compound.

Crystal structure of 10-benzyl-9-(3,4-di-meth-oxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,6,7,9,10-hexa-hydro-acridine-1,8(2H,5H)-dione.

In the acridinedione moiety of the title compound, C32H37NO4, the central di-hydro-pyridine 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 cyclo-hexenone rings adopt envelope conformations, with the tetra-subsituted C atoms as the flap atoms. The 3,4-di-meth-oxy--benzene and benzyl rings are almost normal to the di-hydro-pyridine mean plane, with dihedral angles of 89.47 (9) and 82.90 (11)°, respectively. In the crystal, mol-ecules 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).

9-(2,4-Dinitro-phen-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-1H-xanthene-1,8(2H)-dione.

In the title compound, C(23)H(24)N(2)O(7), the central 4H-pyran ring adopts a flattened boat conformation, whereas both cyclo-hexenone 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 dinitro-benzene ring make a dihedral angle of 85.88 (2)°.

6-Hy-droxy-5-[(2-hy-droxy-4,4-dimethyl-6-oxo-cyclo-hex-1-en-yl)(4-nitro-phen-yl)meth-yl]-1,3-di-methyl-pyrimidine-2,4(1H,3H)-dione.

In the title compound, C21H23N3O7, the pyrimidine-dione ring adopts a screw-boat conformation, whereas the cyclo-hexenone 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 pyrimidine-dione and cyclo-hexenone rings is 58.78 (2)°. The pyrimidine-dione and cyclo-hexenone rings form dihedral angles of 59.94 (3) and 54.73 (2)°, respectively, with the 4-nitro-phenyl ring. Relatively strong intra-molecular O-H⋯O hydrogen bonds are observed. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming a chain along the c-axis direction.

2,2'-[(3-Bromo-4-hy-droxy-5-meth-oxy-phen-yl)methyl-idene]bis-(3-hy-droxy-5,5-dimethyl-cyclo-hex-2-en-1-one).

In the title compound, C(24)H(29)BrO(6), the dihedral angle between the cyclo-hexenone mean planes is 57.63 (2)° while the dihedral angles between the benzene ring and the cyclo-hexenone mean planes are 58.42 (2) and 69.08 (3)°. The two cyclo-hexenone rings both show an envelope conformation, with the C atom bearing two methyl groups as the flap atom in each ring. Two intra-molecular O-H⋯O hydrogen bonds occur. In the crystal, molecules are linked via pairs of O-H⋯O hydrogen bonds, forming inversion dimers.

2,2'-[(4-Eth-oxy-phen-yl)methyl-ene]bis-(3-hy-droxy-5,5-dimethyl-cyclo-hex-2-en-1-one).

In the title compound, C(25)H(32)O(5), the two cyclo-hexenone rings have envelope conformations with the C atom bearing two methyl groups as the flap atom in each ring. Relatively strong intra-molecular O-H⋯O hydrogen bonds are observed.

10-Benzyl-9-(4-eth-oxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,6,7,9,10-hexa-hydro-acridine-1,8(2H,5H)-dione.

In the title compound, C(32)H(37)NO(3), the central dihydro-pyridine ring adopts a nearly planar flattened-boat conformation, whereas both cyclo-hexenone rings adopt half-chair conformations. The mean and maximum deviations from the mean plane of the dihydro-pyridine ring are 0.1252 (9) and 0.188 (1) Å, respectively. The 4-eth-oxy-phenyl and phenyl rings form dihedral angles of 75.20 (4) and 82.14 (5)° with the dihydro-pyridine mean plane, respectively.

9-(4-Hy-droxy-3,5-dimeth-oxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-1H-xanthene-1,8(2H)-dione.

In the title compound, C(25)H(30)O(6), the two fused cyclo-hexa-none 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.