In the title compound, C(25)H(30)O(6), the two fused cyclo-hexa-none rings have envelope conformations, whereas the central pyran ring is roughly planar [mximum deviation = 0.045 (2) Å]. The pyran and benzene rings are almost perpendicular to each other, making a dihedral angle of 86.32 (2)°. In the crystal, molecules are linked via pairs of O-H⋯O hydrogen bonds, forming inversion dimers.

THE TITLE COMPOUND (SYSTEMATIC NAME 7-oxo-3-phenyl-2,6-dioxabicyclo-[3.3.1]nonan-4-yl acetate), C(15)H(16)O(5), is a styryllactone derivative which was isolated from Goniothalamus macrophyllus. The mol-ecule has two fused rings consisting of a tetra-hydro-2H-pyran and a lactone ring, with the benzene ring and the acetyl group attached to the tetra-hydro-2H-pyran ring. The tetra-hydro-2H-pyran r...

The duration of protection afforded by 5 known interferon inducers was deterw•ined. Groups of mice were given a single dose of statolon, maleic acid-divinyl ether copolymer (pyran), polycytidylic/polyinosinic acid (I/C), Newcastle disease virus (NDV), or bacterial endotoxin. These groups and an untrek,3d control group were uniformly challenged with MM virus. Survival data obtained during 20 day...

In the title mol-ecule, C18H16O7, the dioxolane ring adopts an envelope conformation with the dimethyl-substituted C atom as the flap. The furan ring is almost coplanar with the pyran ring, with a dihedral angle of 1.04 (10)° between the planes, and it makes a dihedral angle of 67.97 (11)° with the mean plane of the dioxolane ring. The latter makes a dihedral angle of 67.15 (10)° with the 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 green ...

a novel rice-husk-silica supported n-propyl bipyridinium chloride (rhprbpcl) has been prepared. due to the basicity of rhprbpcl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. the catalyst was characterized by ft-ir, sem and tga analyses. this methodology offers seve...

A comparative study of the secondary metabolism of two Trichoderma spp. with that of the Thctf1 transcription factor gene null mutant of Trichoderma harzianum 34 was carried out in order to deepen our knowledge of the biosynthetic pathway and mode of action of 6-pentyl-2H-pyran-2-one (1) and its derivatives as biocontrol agents. New isolated metabolites have shed light on the detoxification mec...

Pyran covalently linked to cyanogen bromide-activated Sepharose has been shown to be an effective affinity matrix for several viral DNA polymerases. Differential salt elution of viral compared with cellular polymerases, as well as substrate elution, suggests the affinity nature for the matrix. Unlike some other affinity systems described, pyran-Sepharose is totally resistant to nuclease digesti...

In the title hydrate, C19H16N2O4·H2O, the 4H-chromen-4-one segment is slightly twisted, with a dihedral angle between the two six-membered rings of 3.30 (5)°. The dihedral angles between the plane of the pyran-one ring and the hydrazide plane and between the planes of the pyran-one ring and the benzene ring of the p-meth-oxy-benzene unit are 26.69 (4) and 2.23 (3)°, respectively. The mol-ecule ...

In the title compound, C15H9Br2NO3, the chromene unit is not quite planar (r.m.s. deviation from planarity = 0.0888 Å). The di-hydro-pyran ring adopts an envelope conformation with the phenyl-substituted C atom fused to the di-hydro-pyran ring as the flap. The dihedral angle between the plane defined by this C atom and the adjacent C and O atoms and the mean plane of the di-hydro-pyran ring exc...