(6bS*,14R*,14aR*)-Methyl 14-(4-methyl-phen-yl)-7-oxo-6b,6c,7,12b,14,14a-hexa-hydro-1H-pyrano[3,2-c:5,4-c']dichromene-14a-carboxyl-ate

Methyl (6R*,6aR*,12bR*)-2,4-dimethyl-6-(2-methylphenyl)-1,3-dioxo-2,3,4,6a,7,12b-hexahydro-1H,6H-chromeno[4′,3′:4,5]pyrano[2,3-d]pyrimidine-6a-carboxylate

In the title compound, C24H24N2O6, the mean planes of the pyran rings (AandB) are inclined to one another by 69.2 (1)°, while the aromatic ring (D) of the chromene ring system makes dihedral angles of 63.42 (11) and 66.81 (12)° with the pyrimidine (C) and benzene (E) rings, respectively. Pyran ringAhas an half-chair conformation, while pyran ringBhas an envelope conformation, with the spiro C atom as the flap. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a supramolecular three-dimensional network. There are also a number of C—H...π interactions present.

Crystal structures and conformational analyses of three pyranochromene derivatives

The title compounds, C27H20O6, (I) [systematic name: methyl 7-oxo-14-phenyl-1H,7H,14H-pyrano[3,2-c:5,4-c']dichromene-14a(6bH)-carboxyl-ate], C24H22O5, (II) [systematic name: methyl 1-oxo-6-phenyl-2,3,4,12b-tetra-hydro-1H,6H-chromeno[3,4-c]chromene-6a(7H)-carboxyl-ate], and C25H23N3O4, (III) [systematic name: 6-(4-ethyl-phen-yl)-2,4-dimethyl-1,3-dioxo-2,3,4,12b-tetra-hydro-1H,6H-chromeno[4',3':4,5]pyrano[2,3-d]pyrimidine-6a(7H)-carbo-nitrile], are pyran-ochromene derivatives. The central pyran rings (B) of compounds (I) and (III) adopt half-chair conformations, whereas that of compound (II) adopts a sofa conformation. The pyran rings (A) of the chromene ring systems of compounds (II) and (III) adopt half-chair conformations, while that of compound (I) adopts a sofa conformation. The mean plane of the central pyran rings (B) make dihedral angles of 70.02 (6), 61.52 (6) and 69.12 (7)°, respectively, with the mean planes of the chromene moieties (C+A) of compounds (I), (II) and (III). The bicyclic coumarin ring system (C+A+B+E) in compound (I) is almost planar (r.m.s. deviation = 0.042 Å). The carbo-nitrile side chain in compound (III) is very nearly linear, with the C-C N angle being 176.6 (2)°. The cyclo-hexene ring (E), fused with the central pyran ring (B) in compound (II) adopts a sofa conformation. In the mol-ecular structures of compounds (II) and (III), there are C-H⋯O short contacts, which generate S(7) ring motifs. In the crystal structures of the title compounds, mol-ecules are linked by C-H⋯O hydrogen bonds, which generate mol-ecular sheets parallel to the ab plane, with R 4 (3)(28) loops in (I), inversion dimers with R 2 (2)(10) loops in (II) and chains along [010] with R 2 (2)(12) ring motifs in (III). In the crystal structures of (I) and (III), there are also C-H⋯π inter-actions present, leading to the formation of a three-dimensional framework in (II) and to sheets parallel to (101) in (III).

16-Methyl-11-(2-methyl-phen-yl)-14-phenyl-8,12-dioxa-14,15-di-aza-tetra-cyclo-[8.7.0.0(2,7).0(13,17)]hepta-deca-2(7),3,5,13(17),15-penta-ene-10-carbo-nitrile

In the title compound, C₂₈H₂₃N₃O₂, the pyrazole ring makes a dihedral angle of 16.90 (6)° with the phenyl ring to which it is attached. Both di­hydro­pyran rings exhibit half-chair conformations. Intramolecular C—H⋯O interactions generate S(6) and S(8) ring motifs. In the crystal, weak C—H⋯O and C—H⋯π interactions occur.

Methyl 11,14,16-triphenyl-8,12-dioxa-14,15-di-aza-tetra-cyclo-[8.7.0.0(2,7).0(13,17)]hepta-deca-2(7),3,5,13(17),15-penta-ene-10-carboxyl-ate

In the title compound, C₃₃H₂₆N₂O₄, the pyrazole ring makes dihedral angles of 15.13 (7) and 60.80 (7)° with the adjacent phenyl rings. Both di­hydro­pyran rings exhibit half-chair conformations. A weak intra­molecular C—H⋯O inter­action occurs. In the crystal, mol­ecules are linked into inversion dimers through pairs of C—H⋯N inter­actions. Weak C—H⋯π inter­actions are also observed.