The pyran-oside ring in the title compound, C(21)H(24)O(11), has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing is dominated by C-H⋯O inter-actions that lead to the formation of supra-molecular layers in the ab plane.

In the structure of the title compound, C12H12O3, the di-hydro-pyran ring is fused with the benzene ring. The di-hydro-pyran ring is in a half-chair conformation, with the ring O and methyl-ene C atoms positioned 1.367 (3) and 1.504 (4) Å, respectively, on either side of the mean plane formed by the other four atoms. The meth-oxy group is coplanar with the benzene ring to which it is connected ...

3-Acyl-5-( 1 -am inoalkylidene)-4-hydroxy-2 Hpyran-2,6(3 //)-d ione derivatives carrying lipophilic am ino groups were found to be highly potent inhibitors o f photosynthetic electron transport, and bo th the acyl and the am inoalkylidene groups on the pyran ring appeared to be indispensable for high activity. The structural features needed for activity in the 3-acyl-5(l-am inoalkylidene)-4-hyd...

Exhaustive hydro-distillation of the bark, heartwood and fruits of Cryptocarya massoy (Lauraceae) afforded pale yellow-coloured oils in 0.7, 1.2 and 1.0 % yields, respectively. Detailed chemical evaluation of these distillates using GC/MS revealed the major components in the bark and the heartwood oils to be the C-10 (5,6-dihydro-6-pentyl-2H-pyran-2-one) and C-12 (5,6-dihydro-6-heptyl-2H-pyran-...

     A very efficient one-pot three-component synthesis of pyran derivatives has been improved by condensation of aldehydes and malononitrile with dimedone under 80 °C using sucrose as natural and biodegradable catalyst in water. This method offers some advantages including inexpensive, high to quantitative yields, short reaction time, and easy work-up. Therefore, this methodology is entirely g...

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 mol-ecule, C11H10ClFO2, the benzene ring, the F atom and the O atom of the di-hydro-pyran ring are essentially coplanar, with an r.m.s. deviation of 0.007 Å. The di-hydro-pyran ring is in a half-chair conformation. In the crystal, mol-ecules are linked by pairs of weak C-H⋯π hydrogen bonds, forming inversion dimers.

A new method for the synthesis of pyran fused coumarins by 3-bromo-4-hydroxycoumarins as cyclic α-halo ketones based on an organocatalyst assisted three-component tandem reaction is investigated. To the best of our knowledge, cyclic α-halo ketones have not yet been used for the synthesis of pyran fused coumarins.

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)°.

Electrochemical synthesis suggested a mild, green and atom-efficient route to interesting useful molecules, thus avoiding harsh chemical oxidizing reducing agents used in traditional synthetic methods. Organic electrochemistry offers an excellent alternative conventional methods of organic creates modern tool for carrying out synthesis, including cascade multicomponent ones. In this research, n...