X-ray crystallography unequivocally confirmed the stereochemistry of the C atom at position 2 in the carbon scaffold of the title mol-ecule, C(10)H(18)O(4). The pyran-ose ring exists in a chair conformation with the methyl group on the C atom in the 2 position in an equatorial configuration. The absolute stereochemistry was determined from the starting material. The crystal structure consists o...

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-...

Functionalised cyclic enol ethers can be recovered with high levels of enantiocontrol after an asymmetric catalytic [1,3]-rearrangement reaction. These compounds can be further elaborated to a series of carbo- and heterocyclic products in good yield and with excellent levels of stereocontrol.

In the title compound, C(17)H(11)BrN(2)O(2), the five-membered isoxazole ring has an envelope conformation with the C atom bearing the phenyl ring as the flap. The pyran ring has a half-chair conformation. In the chromeno ring system, the dihedral angle between the mean plane of the pyran ring and the benzene ring is 4.68 (2)°. The dihedral angle between the mean planes of the chromeno ring sys...

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 title compound, C(18)H(15)NO(3), the fused benzopyran and pyridine rings are essentially coplanar [r.m.s. deviation = 0.0533 Å with a maximum deviation of 0.080 (1) Å for a benzene C atom]. The cyclo-hexa-none ring adopts an envelope conformation with the dimethyl-substituted C atom 0.660 (2) Å out of the plane formed by the remaining ring atoms (r.m.s. deviation = 0.0305 Å). The dihedra...

In the title compound, C(23)H(20)FNO(4), the fluoro-substituted benzene ring is approximately perpendicular to the mean plane of the 4H-benzo[h]chromene ring system [maximum deviation = 0.264 (1) Å], with a dihedral angle of 83.79 (6)°. The pyran ring adopts a flattened boat conformation. The meth-oxy group is slightly twisted from the attached benzene ring of the 4H-benzo[h]chromene moiety [C-...

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.

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.

In the title compound, C25H21BrN2O2, the fused isoxazolidine ring adopts an envelope conformation with the N atom at the flap and the mean plane of the ring makes dihedral angles of 54.37 (12) and 87.32 (13)°, respectively, with the adjacent phenyl and benzene rings. The tetra-hydro-pyran ring has a half-chair conformation. In the crystal, mol-ecules are linked into a double-column structure al...