In the title compound, C(20)H(23)N(3)O(3), the dihydro-pyran ring adopts half-chair conformation. The chromene system makes a dihedral angle of 87.35 (5)° with the adjacent benzene ring. An intra-molecular N-H⋯O hydrogen bond generates an S(6) motif, which stabilizes the mol-ecular conformation. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds contribute to the stabilization of the pac...

Both independent mol-ecules in the asymmetric unit of the title compound, C(11)H(10)O(4), are almost planar (r.m.s. deviations = 0.011 and 0.033 Å). In both mol-ecules, the hy-droxy group is intra-molecularly hydrogen bonded to the ketonic O atom. The independent mol-ecules are stacked alternately along the a axis, with the centroids of their chromene ring separated by distances of 4.490 (1) an...

In the title compound, C(17)H(15)NO(2)S(2), the 3H-benzo[f]chromene ring system is distinctly twisted; the dihedral angle between the pyran ring and its opposite benzene ring is 9.11 (8)°. The N,N-dimethyl-carbamodithio-ate residue lies almost perpendicular to the pyran ring [dihedral angle = 85.15 (7)°]. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into C(10) chains propagatin...

There are two independent mol-ecules in the asymmetric unit of the title compound, C19H16N2O5S, in which the thia-zole rings make dihedral angles of 80.89 (11) and 84.81 (11)° with the pyrano[3,2-c]chromene ring systems. An intra-molecular N-H⋯O hydrogen bond involving the amino group occurs in each independent mol-ecule. In the crystal, the amino groups are involved in N-H⋯O and N-H⋯N hydrogen...

2-Alkenylphenols react with allenes, upon treatment with catalytic amounts of Pd(II) and Cu(II), to give benzoxepine products in high yields and with very good regio- and diastereoselectivities. This contrasts with the results obtained with Rh catalysts, which provided chromene-like products through a pathway involving a β-hydrogen elimination step. Computational studies suggest that the square...

In the crystal structure of the title compound, C(20)H(16)O(5), the mol-ecule assumes an E configuration with the benzene ring and chromenecarboxyl group located on opposite ends of the C=C double bond. The chromene ring system and benzene ring are oriented at a dihedral angle of 74.66 (12)°. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

The title compound, C(26)H(24)O(5), was isolated from calophyllum inophyllum seeds. In the mol-ecule, the phenyl and 2-methyl-but-2-enoyl groups are almost orthogonal to the chromene fragment [C-C-C-C torsion angles = 81.4 (3) and -90.1 (2)°, respectively]. In the crystal packing, centrosymmetrically related mol-ecules are linked by C-H⋯O contacts into dimers, which are connected via further C-...

In the title compound, C16H12N2O3, the 2H-chromene moiety is essentially planar, with an r.m.s. deviation of the nine constituent atoms from the mean plane of 0.0093 Å, and makes a dihedral angle of 76.84 (3)° with the pendant phenyl ring. An intra-molecular N-H⋯O hydrogen bond helps to determine the conformation of the side chain. In the crystal, N-H⋯O and N-H⋯N hydrogen bonds link the mol-ecu...