Baker-Venkataraman rearrangement chromones, 3, 818  [c.533]

Chromone, 2-alkylamino-5,8-dimethoxy-synthesis, 3, 717 Chromone, 2-amino-aromaticity, 3, 714 tautomerism, 3, 644  [c.581]

Chromone, 2-amino-3-chloro-synthesis, 3, 713 diacetate, 3, 714 Chromone, 3-aroyl-photochemistry, 3, 695 Chromone, 2-benzhydryl-3-benzoyl-photoenolization, 3, 695 Chromone, 3-benzoyl-2-benzyl-photoenolization, 3, 695 Chromone, 3-benzoyl-2-methyl-synthesis, 3, 823 Chromone, 2-benzyl-in photochromic processes, 1, 387 Chromone, 3-benzyl-photolysis, 3, 695 Chromone, 3-bromo-synthesis, 3, 828 Chromone, 3-bromoacetyl-ring opening, 3, 713 Chromone, 3-bromo-2-methyl-reactions  [c.581]

Chromone, 5-hydroxy-2-methyl-biosynthesis, 3, 876 Chromone, 6-hydroxy-2-methyl-reactions  [c.581]

Chromone, 7-hydroxy-2-methyl-bromination, 3, 707 Chromone, 3-hydroxymethylene-synthesis, 3, 821  [c.582]

Chromone, 3-hydroxymethyl-8-methoxy-antiallergic activity, 3, 707 Chromone, 7-methoxy-chlorosulfonation, 3, 708 Chromone, 7-methoxy-2-methyl-chloromethylation, 3, 708 Chromone, 2-methyl-chloromethylation, 3, 697 halogenation, 3, 709 IR spectra, 3, 596 mass spectra, 3, 613 oxidation, 3, 709 reactions  [c.582]

Chromone-2-carboxylic acid, 8-cyano-6-methyl-ethyl ester  [c.582]

Chromone-2-carboxylic acid, 6,8-dibromo-7- hydroxy-ethyl ester  [c.582]

Derivatives of these compounds or thek corresponding quinones are of widespread occurrence in nature. They are abundant in plants and fmits as glucosides, chromones, coumatin derivatives, flavonoids, essential oils, lignins, tannins, and alkaloids (see Alkaloids Coumarin Lignin Oils,essential). They also occur in microorganisms and animals. Many of these compounds have distinct properties and uses, eg, antibiotics (qv), plant-growth factors, insecticides, astringents, antioxidants (qv), toxins, sweeteners (qv), pigments (qv) and dyes, dmgs, and many others (see Dyes and dye intermediates Insect CONTROL technology Pharmaceuticals). Developing uses for the benzenepolyols and derivatives appear particularly valuable in the pharmaceutical and agricultural chemical areas. The most recent appHcations of these compounds are as components of photosensitive compounds in high resolution heat-resistant photoresist compositions.  [c.375]

X = O) (we use an abbreviated and informal nomenclature here—long-established and widely understood) are generated. These systems have complete tt-conjugation, and possess aromatic stabilization in some degree, although precisely to what extent is difficult to quantify. The isomeric structures (28 X = NH, O) are also known, but they are chemically more reactive, behaving as 1,3-dipoles in cycloaddition reactions, and being prone to dimerization and rearrangement. Benzo-fused analogues of these compounds are also long-known and well investigated, as is indicated by the profusion of trivial names by which they are, or have been, known. Thus, the 2/f-l-benzopyran-2-ones (29) are the coumarins, the 4//-l-benzopyran-4-ones (30) are the chromones and the 2-phenyl derivatives (30 R = Ph) of the chromones are the flavones. The dibenzopyrones (31) are known as xanthones.  [c.4]

The fragmentation pattern of isoxazoles on electron impact has been well studied. It has been used as an important tool for the structural assignment of isoxazoles obtained from the reaction of chromones with hydroxylamine 79MI41600, 77JOC1356). For example, the structures of the isoxazoles (387) and (388) were assigned on the basis of their fragmentation patterns. Ions at mje 121 (100%) and mje 93 (19.8%) were expected, and indeed observed, for the isoxazole (388), and an ion at mje 132 (39.5%>) was similarly predicted and observed for the isoxazole (387).  [c.79]

Benzofurans, 4, 531-597, 657-712 chroman synthesis from, 3, 785 chromene synthesis from, 3, 753 chromone synthesis from, 3, 828 CNDO, 4, 536  [c.548]

Benzopyrylium perchlorate, 3-ethyI-reduction, 3, 662 Benzopyrylium salts C NMR, 3, 590 chromene synthesis from, 3, 756 chromone synthesis from, 3, 829 electrophilic substitution, 2, 49 mass spectra, 3, 618 reactions  [c.552]

Chromone, 2,3-dichloro-7-methoxy-synthesis, 3, 825 Chromone, dihydromass spectra, 2, 23 Chromone, 3,5-dihydroxy-2-methyl-selective methylation, 3, 716 Chromone, 5,7-dihydroxy-2-methyl-prenylation, 3, 716 Chromone, 3,7-dimethoxy-2-methyl-reactions  [c.581]

Chromone, N-methyltetrazol-5-yl-antiallergic activity, 5, 836 Chromone, 3-nitro-reactions  [c.582]

Chromone, 3-(tetrazol-5-yl)-antiallergic activity, 5, 836 degradation, 5, 815 Chromone, 3,5,7-trimethoxy-2-methyl-photolysis, 3, 695  [c.582]

Chromone-2-carbaldehyde, 3-methyl-synthesis, 3, 709 Chromonecarbaldehydes Knoevenagel condensation, 3, 711 Chromone-3-carbaldehydes mass spectra, 3, 615 oxidation, 3, 709 reactions, 3, 712 Schiff bases, 3, 712 synthesis, 3, 821 Chromone-2-carbonyl chloride Grignard reaction, 3, 711 Chromonecarboxamide, N-tetrazolyl-antiallergic activity, 3, 707 Chromone-2-carboxylic acid, 3-chloro-ethyl ester  [c.582]

See pages that mention the term Chromones : [c.558]    [c.381]    [c.254]    [c.23]    [c.121]    [c.78]    [c.79]    [c.12]    [c.12]    [c.12]    [c.12]    [c.12]    [c.13]    [c.13]    [c.509]    [c.509]    [c.536]    [c.551]    [c.567]    [c.579]    [c.579]    [c.581]    [c.581]    [c.581]    [c.581]    [c.581]    [c.581]    [c.581]    [c.581]    [c.582]    [c.582]    [c.582]    [c.582]    [c.582]   
See chapters in:

The organic chemistry of drug synthesis Vol.4  -> Chromones