The title compound, C(24)H(29)NO(7), is asymmetric with a chiral centre located in the pyran ring and crystallizes as a racemate. The coumarin ring system and the fused pyran ring make a dihedral angle of 10.46 (8)°. A short intra-molecular N-H⋯O hydrogen bond between the amino group and the vicinal carbonyl group generates an S(6) ring. Inter-molecular C-H⋯O inter-actions contribute to the sta...

In the title compound, C(21)H(22)O(5), the mean planes of the pyran and dimeth-oxy-phenyl rings are nearly perpendicular to one another, with the dihedral angle between them being 88.21 (8)°. The pyran ring adopts a boat conformation whereas the two fused cyclo-hexane rings adopt envelope conformations. In the crystal, mol-ecules are linked into a three-dimensional network by inter-molecular C-...

The title compound, C23H20N2O6, crystallizes with two mol-ecules in the asymmetric unit in which the dihedral angles between the mean planes of the pyran and phenyl rings are 66.6 (1) and 61.9 (1) °. The fused pyrone and pyran rings each adopts a sofa conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules, forming a two-dimensional network parallel to [001].

The title compound, C(21)H(21)ClO(7)·C(2)H(5)OH was synthesized by the condensation reaction between helicid [systematic name: 4-(β-d-allopyranos-yloxy)benzaldehyde] and 4-chloro-aceto-phen-one in ethanol. In the mol-ecular structure, the pyran-oside ring adopts a chair conformation. In the crystal structure, the molecules are linked by inter-molecular O-H⋯O hydrogen bonds involving the OH grou...

The title compound, C(26)H(24)O(3), was synthesized via the coupling of 2-methoxy-benzaldehyde, 2-naphthol and 5,5-dimethyl-cyclo-hexane-1,3-dione. The pyran ring adopts a boat conformation, while the cyclo-hexenone ring is in an envelope conformation. The 2-methoxy-phenyl ring is almost perpendic-ular to the plane through the four C atoms of the pyran ring [dihedral angle = 88.76 (9)°].

In the mol-ecule of the title compound, C(16)H(13)N(3)O(4), the atoms of the spiro pyran ring are nearly planar with a maximum deviation of 0.095 (2) Å. The indole and pyran rings are oriented at a dihedral angle of 87.3 (9)°. In the crystal, mol-ecules are linked by inter-molecular N-H⋯N and N-H⋯O hydrogen bonds.

A novel bicyclization of 2-(2-(hydroxymethyl)-1-methylene-2,3-dihydro-1H-inden-2-yl)ethanol with aldehydes in the presence of 10 mol% BF3·OEt2 in dichloromethane at 0-25 °C affords the biologically relevant indeno[2,1-c]pyran scaffolds in good yields with high selectivity. Similarly the bicyclization of 2-(1-(hydroxymethyl)-2-methylenecyclopentyl)ethanol with aldehydes generates the correspondi...

Heating 4-methoxy-1-naphthol with a 1,1-diarylprop-2-yn-1-ol gave the 2,2-diaryl-6-methoxy-2H-naphtho[1,2-b]pyran together with the novel merocyanine, (E)-2-[3',3'-bis(aryl)allylidene]-4-methoxynaphthalen-1(2H)-one. Brief UV-irradiation of the pyran favoured the formation of the (Z)-merocyanine with longer irradiation and/or acidic conditions favouring the (E)-isomer.

The title compound, C(25)H(23)NO(5), comprising two stereogenic carbon atoms of the same configuration, crystallizes in a centrosymmetric space group as a racemate. The six-membered pyran ring and the five-membered isoxazole ring adopt sofa and twisted conformations, respectively. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is...

In the mol-ecular structure of the title compound, C(25)H(21)NO(4), the pyran ring adopts a flattened boat conformation, while the cyclo-hexenone ring is in an envelope conformation. The 4-nitro-phenyl ring is almost perpendicular to the pyran ring [dihedral angle = 89.39 (1)°]. In the crystal, mol-ecules are connected by inter-molecular C-H⋯O hydrogen bonds.