In the title compound, C(20)H(24)O(5), the six-membered pyran-ose ring adopts a chair conformation. The dihedral angle between the planes of the phenyl groups of the benzyl substituents is 63.1°. Two types of inter-molecular O-H⋯O hydrogen bonds lead to the formation of infinite chains along the b axis. Only weak C-H⋯O contacts exist between neighboring chains.

In the title compound, C(31)H(29)NO(5), the methyl carboxyl-ate and dimethyl-amino groups on the naphtho-pyran group are almost coplanar with the naphtho-pyran ring system [r.m.s. deviations = 0.08 (2) and 0.161 (2) Å, respectively]. The dihedral angle between the methyl carboxyl-ate and dimethyl-amino groups is 4.9 (1)°. The pyran ring has an envelope conformation with the quaternary C atom ou...

In the title compound, C(27)H(27)NO(4), the five-membered isoxazole ring adopts an envelope conformation and the six-membered pyran ring adopts a half-chair conformation. The dihedral angle between the mean planes of the isoxazole ring and the chromene ring system is 54.95 (4)°.

In the title compound, C25H27ClO3, each of the cyclo-hexenone rings adopts an envelope conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms. The C=C double bond is in the trans conformation. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into chains running parallel ...

In the title compound, C(16)H(14)O(4)·H(2)O, the dihedral angle betwen the benzene rings is 71.4 (6)°. The pyran ring is in a sofa conformation. In the crystal, O-H⋯O hydrogen bonds connect the components into a two-dimensional network parallel to (010), incorporating C(2) (2)(4) and C(2) (2)(11) chains. In addition, weak C-H⋯O, C-H⋯π and π-π stacking inter-actions [centroid-centroid distance =...

In the title compound, C(23)H(25)NO(5), the pyran ring adopts a flattened boat conformation, while the two cyclo-hexenone rings are in envelope conformations. The 3-nitro-phenyl ring is almost perpendicular to the pyran ring, making a dihedral angle of 87.1 (3)°.

In the title chromenone derivative, C(10)H(8)O(2), the two fused six-membered rings are coplanar, with a mean deviation of 0.0261 (1) Å from the plane through the non-H atoms of the rings. The carbonyl and methyl substituents of the pyran ring also lie close to that plane, with the O and C atoms deviating by 0.0557 (1) and 0.1405 (1) Å, respectively. In the crystal, weak C-H⋯O contacts form cha...