In the title compound, C(28)H(22)O(6), the chromeno ring system is almost planar, with a dihedral angle between the mean planes of the pyran and benzene rings of 1.87 (8)°. The pyran ring bearing the methyl-phenyl substituent has a half-chair conformation while the other pyran ring has an envelope conformation with the tetra-substituted C atom as the flap. The benzene ring of the chromeno ring ...

The immunomodulator pyran markedly protected 5-week-old mice from lethal intravenous infection with herpes simplex virus type 2. The 50% lethal dose was increased almost 100-fold in pyran-treated mice as compared with controls. Although the protection was not as marked in older mice (10 and 16 weeks old), there was a significant increase in mean survival time. When the pathogenesis of herpesvir...

Mouse resistance to foot-and-mouth disease virus (FMDV) was induced by intraperitoneal injections of pyran copolymer. A biphasic pattern of protection occurred with greatest resistance 4 and 48 hr after injection of this polyanion. Viremia was not detectable in pretreated mice challenge-exposed with FMDV. Incubation of virus with pyran did not alter viral infectivity in mice or tissue culture. ...

Tetrahydro-4H-chromene-3-carbonitrile derivatives 4a-c where prepared from the reaction of 1,4-cyclohexane dione (1), malononitrile (2) and either benzaldehyde (3a), 2-chlorobenzaldehyde (3b) or 4-methoxybenzaldehyde (3c) in ethanol containing triethylamine. Compound 4b was used to prepare pyrazole, pyrimidine thiazole derivatives. Moreover, tetrahydrobenzo[d]thiazole derivative 18 (1) with ele...

The title compound, C(14)H(11)ClN(2)O(3)S, with fused thiophene and pyran rings, was synthesized via the condensation of dihydro-thio-phen-3(2H)-one 1,1-dioxide and 2-(3-chloro-benz-yl-idene)malononitrile catalysed by triethyl-amine in ethanol. The thio-phene ring adopts an envelope conformation and the pyran ring is planar (r.m.s. deviation = 0.0067 Å). The dihedral angle between the pyran and...

A series of 1H amorphous tri-phenyl pyridine (HAPPY) dyes have been synthesized from luminescent triphenyl-group-containing 2-methyl-6-styryl-substituted-4H-pyran-4-ylidene derivatives in reactions with benzylamine and investigated for suitability as solution-processable light-emitting medium components thin films amplified spontaneous emission (ASE). Conversion a 4H-pyrane ring into 1H-pyridin...

Abstract Background The nano-sized particles enhance the exposed surface area of active part catalyst, thereby increasing contact between precursors and catalyst considerably. In this study, nano-SiO 2 /1,5-diazabicyclo[4.3.0]non-5-en was synthesized, characterized used as a heterogeneous nanocatalyst for synthesis tetrahydrobenzo[ b ]pyran derivatives. Fourier Transform Infrared Spectroscopy, ...