Coumarins chromones

Benzopyrylium Salts, Coumarins, Chromones, Flavonoids and Related Compounds... 

Carum carvi L. Ye Hao (Caraway) (fruit, aerial part) Essential oil, d-carvone, coumarin, chromone, polyacetylene, hemiarin, scopoletin, umbelliferone, d-limonene, phytosterols.48-50-250-450 Carminative, treat stomach pain. 

Ligusticum jeholense (Nakai et Kitag.) Nakai et Kitag. L. pyrenacum Couan. L. sinense Oliv. L. tenuissimum (Nakai) Kitag. Gao Ben (root) Nothosmymol, coumarin, chromone, polyacetylene.33-259 Induce diaphoresis, for gout, an anodyne, emmenagogue, sedative. 

Baba, K., Y. Yoneda, M. Kozawa, E. Fujita, N. H. Wang, and C. Q. Yuan. 1989. Studies on Chinese traditional medicine Fang-Feng . II. Comparison of several Fang-Feng by coumarins, chromones, and polyacetylenes. Shoyakugaku Xasshi 43 216-221. 

The spectra of chromone and many of its derivatives consist of four bands centred around 205, 225, 240 and 300 nm. The major absorption peaks at 240 and 300 nm are separated by a minimum at ca. 270 nm. In contrast to coumarins, chromones do not show a second minimum. 

Unlike coumarin, chromone (206) undergoes efficient unsensitized photoaddition to tetramethylethylene, cyclopentene, ketene dimethyl acetal, and but-2-yne.180 The major product of such an addition to tetramethylene is the cis-fused cyclobutane derivative (207) the formation of the two minor products (208 and 209) is easily rationalized. Added benzophenone has no visible effect on this cycloaddition, which is therefore believed to involve the attack of triplet chromone on the ground-state alkene. Photoaddition to furo-chromones has also been studied,179 and the photosensitized cyclo-... 

Becker and coworkers have published198 a very thorough study of the photophysics and photochemistry of coumarins, chromones and their thione homologues. 

Few of these species are strictly aromatic, but reactivity with electrophiles resembles that of aromatic compounds. Much of the discussion that follows will be devoted to the pyrones and thiopyrones (the fused benz-derivatives, coumarins, chromones, flavones, and isoflavones, will be covered in Part 3). 

Coumarins, chromones, and isocoumarins react with both nucleophiles and electrophiles in much the same way as do quinolones and isoquinolones. 

Natural Prenyl Coumarins, Chromones and related Structures... 

BTCYIJC and POI.YCYCLIC COUMARINS. CHROMONES. TSOFIAVONES. FI.AVONES. TETRAI.01VES... 

The solid state photocyclodimerization of coumarin, chromone and chro-manone derivatives have been reported in this period. " Topochemical photodimerization of 4-chromanone derivatives (269) from p-type structures alforded onri-head-to-tail [2 + 2] cyclodimers (270) in high yields, although an/i-head-to-head cyclodimers (271) were obtained in acetonitrile " " ... 

Eshiett, I. T., and D. A. H. Taylor The Isolation and Structure Elucidation of Some Derivatives of Dimethylallyl-Coumarin, Chromone, Quinoline, and Phenol from Fagara Species and from Cedrelopsis grevei. J. Chem. Soc. (C), 1968, 481. 

Eshiett I T, Taylor D A H 1968 The isolation and structure elucidation of some derivatives of dimethyl-allyl-coumarin, chromone, quinoline, and phenol from Fagara species, and from Cedrelopsis grevei. J Chem Soc (C) 481-484... 

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