In the title compound, tetra-hydro-seselin, C14H16O3, a pyran-ocoumarin [systematic name: 8,8-dimethyl-3,4,9,10-tetra-hydro-2H,8H-pyrano[2,3-f]chromen-2-one] obtained from the hydrogenation of seselin in the presence of Pd/C in MeOH at room temperature, the dihedral angle between the central benzene ring and the best planes of the outer fused ring systems are 6.20 (7) and 10.02 (8)°. In the cry...

In the mol-ecule of the title compound, C(20)H(10)BrN(3)O(4)·C(3)H(7)NO, the spiro pyran ring adopts a twist conformation. The indole and coumarin ring systems are each nearly planar, and are oriented at a dihedral angle of 79.29 (3)°. In the crystal structure, inter-molecular N-H⋯O, N-H⋯N, C-H⋯O and C-H⋯N hydrogen bonds link the mol-ecules.

The title compound, C(25)H(22)N(2)O(3), with three stereogenic centres, crystallizes in a centrosymmetric space group as a racemate. The pyran ring adopts a sofa conformation and the five-membered isoxazole ring exhibits an envelope conformation. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is 10.54 (9)°. In the crystal, no sig...

Two high-yielding strategies for the synthesis of 4H-anthra[1,2-b]pyran antibiotics have been developed giving access to novel antitumor agent (ED(50) 1.5 microm) and to (S)-espicufolin (3). A key step for the assembly of the tetracyclic 4H-anthra[1,2-b]pyran-4,7,12-trione skeleton is the nucleophilic addition of an aryl lithium species onto an aldehyde which allows the introduction of either a...

In the title compound, C23H20N2O6, the fused pyrone and pyran rings each adopt a sofa conformation. The dihedral angle between the mean planes of the pyran and phenyl rings is 61.9 (1)°. In the crystal, mol-ecules are linked by two pairs of C-H⋯O hydrogen bonds, forming dimers. These dimers are linked via a third C-H⋯O hydrogen bond, forming a two-dimensional network parallel to (10-2).

The asymmetric unit of the title compound, C26H28O6·2CH3OH, contains two independent methyl 6-O-trityl-α-d-gluco-pyran-oside mol-ecules and four methanol solvent mol-ecules. The rings of two methyl α-d-gluco-pyran-oside adopt chair conformations. In the crystal, extensive intra- and inter-molecular O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular archi...

In the title compound, C10H5ClO3, a chlorinated 3-formyl-chromone derivative, all atoms are essentially coplanar (r.m.s. deviation = 0.032 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.0598 (14) Å] being for a pyran-ring C atom. In the crystal, mol-ecules are linked through stacking inter-actions along the b axis [shortest centroid-centroid distance between ...

The asymmetric unit of the title compound, C(25)H(22)OS, comprises two similar 4-(4-methoxy-phen-yl)-4-methyl-2,6-diphenyl-4H-thio-pyran mol-ecules. In each, the six-membered thio-pyran ring adopts a planar conformation (r.m.s. deviation of 0.041Å for the ring in one mol-ecule and 0.008 Å in the other). The methoxy-phenyl substituent is in a pseudo-axial position. The crystal studied is an inve...