Showing papers on "Pyran published in 1973"
60 citations
28 citations
TL;DR: The approach, which affords a good yield of L-fucose from the readily available D- Galactose, is also of theoretical interest in that it involves the formal inversion of the D-galactose molecule to produce derivatives of L,fucitol.
19 citations
16 citations
TL;DR: In this article, photosensitized oxygenation of α-pyran (l) (2.5,5,8a,tetramethyl-6,7,8,8-8, 8a-tetrahydro-5H- l-benzopyran), in methanol using rose bengal, rapidly formed a stable peroxide (2).
Abstract: Photosensitized oxygenation of α-pyran(l) (2,5,5,8a-tetramethyl-6,7,8,8a-tetrahydro-5H- l-benzopyran), in methanol using rose bengal, rapidly formed a stable peroxide (2).The peroxide (2) gave 6,6-dimethyl-8-undecene-2,7,10-trione(11) at 140°C in xylene, and 8(or 9)-methoxy or hydroxy derivatives of 6,6-dimethyl-undecane-2,7,10-trione (12a or b) by hydrochloric acid.These triketones (11 and 12a) were also obtained by a photo-reaction from the peroxide(2).
14 citations
Patent•
18 Jul 1973
TL;DR: The compounds of this invention are alkoxy dibenzo(b,d)pyrans having pharmacological activity such as central nervous system activity, antiarthritic and anti-inflammatory activity as discussed by the authors.
Abstract: The compounds of this invention are alkoxy dibenzo(b,d)pyrans having pharmacological activity such as central nervous system activity, anti-arthritic and anti-inflammatory activity. A preferred compound is 1-hydroxy-7,8,9,10-tetrahydro-3-(1methylhexyloxy)-6,6,9-trimethyl-6H -dibenzo(b,d)pyran.
12 citations
TL;DR: In this article, the action of phosphorus oxychloride in DMFA on 4-hydroxy-3-nitrocoumarin has given 4-chloro-3 -nichrome-nocoumarins, by the reaction of which with amines and ammonia 4-amino-3 nocoumins have been synthesized; some physicochemical properties have been studied.
Abstract: The action of phosphorus oxychloride in DMFA on 4-hydroxy-3-nitrocoumarin has given 4-chloro-3-nitrocoumarin, by the reaction of which with amines and ammonia 4-amino-3-nitrocoumarins have been synthesized; some of their physicochemical properties have been studied.
12 citations
TL;DR: Pentacarbonyl-(6-ethoxy-3,4-diphenylpyran-2-ylidene)molybdenum(0) is converted into 4,5-diphynyl-2pyrone by sodium hydroxide or by trifluoroacetic acid, and oxidised to 6-thoxy-4,5diphensyl- 2-pyrones by lead tetra-acetate as discussed by the authors.
Abstract: Pentacarbonyl(diphenylcyclopropenylidene)chromium(0)(1a) and the corresponding molybdenum complex (1b) have been synthesised and converted, by reaction with pyridinium ylides, into the pyran-2-ylidene complexes (2), a new type of carbene complex stabilised by 6 π-electron delocalisation. The 6-ethoxy-groups in the pyran-2-ylidene complexes (2b and e) are readily displaced by nucleophiles such as methanol, ammonia, ethylamine, morpholine, and phenyl-lithium. Pentacarbonyl-(6-ethoxy-3,4-diphenylpyran-2-ylidene)molybdenum(0) is converted into 4,5-diphenyl-2-pyrone by sodium hydroxide or by trifluoroacetic acid, and oxidised to 6-ethoxy-4,5-diphenyl-2-pyrone by lead tetra-acetate. Pentacarbonyl-(3,4,6-triphenylpyran-2-ylidene)molybdenum(0) reacts with N-phenacylpyridinium bromide and triethylamine to give 2-phenacylidene-3,4,6-triphenyl-2H-pyran (6). The complex also reacts with benzyne in a Diels–Alder reaction to give 1,2,4-triphenylnaphthalene and hexacarbonylmolybdenum. The reactivity of the cyclopropenylidene and pyranylidene complexes is compared with that of the corresponding carbonyl compounds.
10 citations
Patent•
29 Jun 1973TL;DR: In this paper, the ortho-phenyl substituent of the starting phenol or thiophenol was used as a stabilizer and antioxidant for stabilizing aldehyde or ketone reactant.
Abstract: Phenols and thiophenols having an ortho-phenyl substituent react with most aldehydes and ketones in very strongly acidic liquid media to form a dibenzopyran or dibenzothiopyran. The dibenzopyrans, but not the dibenzothiopyrans, can be isomerized to their corresponding fluorenols. The pyran or thiopyran ring can be cleaved chemically or electrochemically to produce phenols and thiophenols which have an ortho substituent in the ortho position of the phenyl substituent of the starting phenol or thiophenol which is characteristic of the aldehyde or ketone reactant. These products as well as the fluorenols, being phenolic bodies, are useful as stabilizers and antioxidants.
9 citations
TL;DR: Complexes of the type MX,(phenacyl kojate) have been prepared where MX = NaCl, KCl, NH4Cl, NaBr, KBr, RbBr, NaI, and KI as discussed by the authors.
Abstract: Complexes of the type MX,(phenacyl kojate) have been prepared where MX = CsBr, NH4Br, RbI, CsI, NH4I, NaNCS, KNCS, RbNCS, and CsNCS. When MX = NaCl, KCl. RbCl, CsCl, NH4Cl, NaBr, KBr, RbBr, NaI, and KI, complexes of the type MX2,2(phenacyl kojate) are formed.
7 citations
Patent•
18 Jul 1973
TL;DR: A preferred compound of this invention is 3-(1,2-dimethylhept-1-enyl)-1-hydroxy-7,8,9,10-tetrahydro-6,6,9trimet hyl-6H-dibenzo[b,d]pyran.
Abstract: The compounds of this invention are 3-alkenyl dibenzo[b,d]pyrans having pharmacological activity such as central nervous system activity. A preferred compound of this invention is 3-(1,2-dimethylhept-1-enyl)-1-hydroxy-7,8,9,10-tetrahydro-6,6,9-trimet hyl-6H-dibenzo[b,d]pyran.
Patent•
18 Jul 1973
TL;DR: The compounds of this invention are 2-aminomethyl dibenzo(b, d)pyrans having pharmacological activity such as central nervous system activity as discussed by the authors.
Abstract: The compounds of this invention are 2-aminomethyl dibenzo(b, d)pyrans having pharmacological activity such as central nervous system activity. A preferred compound of this invention is 2-(N, N-dimethylaminomethyl)-3-(1,2-dimethylheptyl)-1-hydroxy-7,8,9,10tetrahydro -6,6,9-trimethyl-6H-dibenzo(b,d)pyran.
TL;DR: In this paper, the proton magnetic resonance spectrum of 4-t-butyl-5,6-dihydro-4H-pyran has been analyzed with the aid of the paramagnetic shift reagent Eu(fod)3.
Abstract: The proton magnetic resonance spectrum of 4-t-butyl-5,6-dihydro-4H-pyran has been analyzed with the aid of the paramagnetic shift reagent Eu(fod)3. All hydrogen-hydrogen spin-spin coupling constants are reported and a conformation is suggested which is consistent with these data.
TL;DR: In this paper, the synthesis and oxidation of substituted 2,3-dihydro-4H-pyran-4-ones were described, and the reaction of crotonoyl chloride with β-ketoester gave dihydro-γ-polypyrone (I) is oxidized, hydrolyzed and subsequently decarboxylated to give 6-methyl maltol (IV).
Abstract: The synthesis and oxidation of substituted 2,3-dihydro-4H-pyran-4-ones are described. The reaction of crotonoyl chloride with β-ketoester gave dihydro-4H-pyran-4-ones (I). Dihydro-γ-pyrone (Ia) is oxidized, hydrolyzed, and subsequently decarboxylated to give 6-methyl maltol (IV).
Patent•
24 May 1973
TL;DR: New compounds of the formula ##SPC1## wherein Ar is selected from the group consisting of phenylethyl, furyl, methylfuryl, thienyl, pyrrolyl, naphthyl etc. as discussed by the authors.
Abstract: New compounds of the formula ##SPC1## Wherein Ar is selected from the group consisting of phenylethyl, furyl, methylfuryl, thienyl, pyrrolyl, naphthyl, hydroxynaphthyl, and phenyl substituted by at least one member selected from the group consisting of halogen, hydroxyl, cyano, trifluoromethyl, akyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, carbamoyl, amino of the formula --NR'R", alkoxycarbonyl of the formula --CO--OR' wherein R'and R"are each alkyl of 1-4 carbon atoms, and alkylenedioxy of the formula --O--R '"--O-- wherein R'" is alkylene of 1-4 carbon atoms, provided that said substituted phenyl is not 3,4-di-methoxyphenyl, and the addition salts thereof with the cation of an organic or inorganic base inhibit the enzyme activities of tyrosine hydroxylase and dopamine β-hydroxylase and are useful chemotherapeutic agents in the treatment of essential hypertension.
Patent•
09 Jul 1973
TL;DR: Indenopyran- and indenothiopyranalkylamine derivatives characterized by having an amino(lower)alkyl radical attached to the 1 position of an indeno[2,1-c]pyran or indeno [2, 1-c]-thiopyrin nucleus are disclosed as discussed by the authors.
Abstract: Indenopyran- and indenothiopyranalkylamine derivatives characterized by having an amino(lower)alkyl radical attached to the 1 position of an indeno[2,1-c]pyran or indeno[2,1-c]thiopyran nucleus are disclosed. Also included are the corresponding derivatives having an indeno[1,2-c]pyran and an indend[1,2-c]-thiopyran nucleus. The amino portion of the amino(lower)alkyl radical may be further substituted with one or two lower alkyl groups or incorporated into a heterocyclic amine radical. The derivatives are further substituted at position 1 and may be optionally substituted at positions 3, 4, 5, 6, 7, 8, and 9. The indenopyran- and indenothiopyranalkylamine derivatives of this invention are useful antidepressant agents. Methods for their preparation and use are disclosed.
Patent•
26 Dec 1973TL;DR: A radiation sensitive recording material contains a layer of a layer-forming substance and incorporated therein an organic halogen compound capable of producing hydrogenhalide when struck by high energy radiation.
Abstract: A radiation sensitive recording material contains a layer of a layer-forming substance and incorporated therein an organic halogen compound capable of producing hydrogenhalide when struck by high energy radiation, and a chromogenic arylvinyl pyran or arylvinylthio pyran which changes its color by reaction with hydrolide. The material provides records with high stability.
TL;DR: 3-O-Methylgalangin on reaction with prenyl bromide in the presence of methanolic methoxide gives 6,8-di-C-prenyl and 6-C -prenYL derivatives in 17% and 10% yields respectively; with 2-hydroxy-2-methylbut-3-ene it affords an 8-C prenyl derivative besides the above two compounds as discussed by the authors.
Abstract: 3-O-Methylgalangin on reaction with prenyl bromide in the presence of methanolic methoxide gives 6,8-di-C-prenyl and 6-C-prenyl derivatives in 17% and 10% yields respectively; with 2-hydroxy-2-methylbut-3-ene it affords an 8-C-prenyl derivative besides the above two compounds. The above di-C-prenyl derivative on oxidative cyclization with DDQ yields a mixture of a linear pyran (3-O-methylsericetin) and an angular pyran (3-O-methylisosericetin).
Patent•
01 Aug 1973
TL;DR: In this paper, a MICROBIAL TRANSFORMATION of 1-HYDROXY-3-N-PENTYL - 6,6,9- TRIMETHYL-6A,7,10,10A-TETRAHYDRODIBENZO (B,D)PYRAN is described.
Abstract: THE COMPOUND 1,4''- DIHYDROXY -3-N-PENTYL-6,6,9TRIMETHYL - 6A,7,10,10A - TETRAHYDRODIBENZO (B,D)PYRAN, WHICH CAN BE PREPARED BY MICROBIAL TRANSFORMATION OF 1-HYDROXY-3-N-PENTYL - 6,6,9- TRIMETHYL-6A,7,10,10A-TETRAHYDRODIBENZO (B,D)PYRAN. THE COMPOUND IS USEFUL AS AN ANTI-DEPRESSANT AGENT,
Patent•
03 Dec 1973
TL;DR: In this article, 2-(N-2-Cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H-pyran-4one and metal chelates thereof are effective agents for controlling undesirable fungi and bacteria.
Abstract: 2-(N-2-Cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H-pyran-4one and metal chelates thereof are effective agents for controlling undesirable fungi and bacteria.
TL;DR: The quantum yield of di(pyranylidene) formation was concentration-dependent in dioxane, while in benzene, it was independent of the concentration.
Patent•
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18 Jul 1973
TL;DR: The compounds of this invention are dibenzo(b,d)pyrans having pharmacological activity such as central nervous system activity as mentioned in this paper. But they are not suitable for use in medical applications.
Abstract: The compounds of this invention are dibenzo(b,d)pyrans having pharmacological activity such as central nervous system activity. A preferred compound is 3-(1,2-dimethylheptyl)-7,8,9,10tetrahydro-6,6,9-trimethyl-6H -dibenzo(b,d)pyran.
TL;DR: Die Umsetzung der Acetylverbindung (I) mit Oxalsaurediathylester (II) und anschliesende Behandlung mit Salzsaure geben den Pyranocarbonsaureester (III), der zur Carbonsaure (IV) verseift wird.
Abstract: Die Umsetzung der Acetylverbindung (I) mit Oxalsaurediathylester (II) und anschliesende Behandlung mit Salzsaure geben den Pyranocarbonsaureester (III), der zur Carbonsaure (IV) verseift wird.