- SYNTHESIS OF 3-METHYLGLUTARIC ACID
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4-Methyltetrahydropyran has been synthetized by catalytic hydrogenation of a mixture of the isomeric 4-methyl-5,6-dihydro- and 4-methylenetetrahydropyrans.Oxidative degradation then led to 3-methylglutaric acid.
- Ibatullin, U. G.,Syurina, L. V.,Vasi'leva, S. A.,Safarov, M. G.
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Read Online
- METHOD FOR PRODUCING CYCLIC ETHER
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A method for producing a cyclic ether represented by formula (2) includes reacting a 2-hydroxy cyclic ether, represented by formula (1), with hydrogen in the presence of a catalyst.
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Paragraph 0053-0056
(2020/12/14)
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- METHOD FOR PRODUCING ACETAL COMPOUND BY USING 4-METHYLTETRAHYDROPYRAN AS SOLVENT
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PROBLEM TO BE SOLVED: To provide a method for producing an acetal compound which is higher in safety and can be applied to a highly polar reaction raw material or the like. SOLUTION: There is provided a method for producing an acetal compound by reacting an alcohol compound, a thiol compound or an amine compound with a carbonyl compound in 4-methyltetrahydropyran. According to the production method of an acetal compound of the present invention, an acetal compound higher in safety can be produced under a mild reaction condition by using 4-methyltetrahydropyran having low toxicity and the method can be widely applied to a highly polar raw material. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0035
(2017/01/02)
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- METHOD FOR PRODUCING ESTER BY USING 4-METHYLTETRAHYDROFURAN AS SOLVENT
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PROBLEM TO BE SOLVED: To provide a method for producing an ester which is higher in safety and can be applied to a highly polar reaction raw material or the like. SOLUTION: There is provided a method for producing an ester by reacting an alcohol and a carboxylic acid in 4-methyltetrahydropyran. By using 4-methyltetrahydropyran as a reaction solvent, an ester can be produced more safely and the method is applicable to a highly polar reaction raw material. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0021
(2016/10/08)
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- METHOD FOR PRODUCING ALKYL GRIGNARD REAGENT USING 4-METHYLTETRAHYDROPYRAN AS SOLVENT
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PROBLEM TO BE SOLVED: To solve the problems in the production of a Grignard reagent by using an alkyl iodide compound and magnesium. SOLUTION: There is provided a method for producing a Grignard reagent represented by the following formula (2), RMgI (2) by reacting an alkyl iodide compound represented by the following formula (1), RI (1) (where, R represents a methyl group or an ethyl group) and magnesium in 4-methyltetrahydropyran. According to the present invention, a Grignard reagent can be easily produced, the cost of apparatus and equipment can be reduced and the reaction operation in the subsequent process can be simplified. Further, since 4-methyltetrahydropyran as a solvent can be reused, the amount used of the solvent can be reduced. COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0028
(2018/11/22)
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- 4-METHYLTETRAHYDROPYRAN COMPOSITION
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PROBLEM TO BE SOLVED: To solve the problem of accumulation of a peroxide generated in the storage of an ether compound and especially, to solve the problem of generation and accumulation of a peroxide due to the autoxidation of a cyclic ether compound. SOLUTION: There is provided a 4-methyltetrahydropyran composition composed of a 4-methyltetrahydropyran compound and an antioxidant. COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0021
(2018/12/05)
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- Experimental investigation of the low temperature oxidation of the five isomers of hexane
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The low-temperature oxidation of the five hexane isomers (n-hexane, 2-methyl-pentane, 3-methyl-pentane, 2,2-dimethylbutane, and 2,3-dimethylbutane) was studied in a jet-stirred reactor (JSR) at atmospheric pressure under stoichiometric conditions between 550 and 1000 K. The evolution of reactant and product mole fraction profiles were recorded as a function of the temperature using two analytical methods: gas chromatography and synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Experimental data obtained with both methods were in good agreement for the five fuels. These data were used to compare the reactivity and the nature of the reaction products and their distribution. At low temperature (below 800 K), n-hexane was the most reactive isomer. The two methyl-pentane isomers have about the same reactivity, which was lower than that of n-hexane. 2,2-Dimethylbutane was less reactive than the two methyl-pentane isomers, and 2,3-dimethylbutane was the least reactive isomer. These observations are in good agreement with research octane numbers given in the literature. Cyclic ethers with rings including 3, 4, 5, and 6 atoms have been identified and quantified for the five fuels. While the cyclic ether distribution was notably more detailed than in other literature of JSR studies of branched alkane oxidation, some oxiranes were missing among the cyclic ethers expected from methyl-pentanes. Using SVUV-PIMS, the formation of C 2-C3 monocarboxylic acids, ketohydroperoxides, and species with two carbonyl groups have also been observed, supporting their possible formation from branched reactants. This is in line with what was previously experimentally demonstrated from linear fuels. Possible structures and ways of decomposition of the most probable ketohydroperoxides were discussed. Above 800 K, all five isomers have about the same reactivity, with a larger formation from branched alkanes of some unsaturated species, such as allene and propyne, which are known to be soot precursors.
- Wang, Zhandong,Herbinet, Olivier,Cheng, Zhanjun,Husson, Benoit,Fournet, Rene,Qi, Fei,Battin-Leclerc, Frederique
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p. 5573 - 5594
(2014/08/18)
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- PRODUCTION PROCESS OF TETRAHYDROPYRAN COMPOUND AND TETRAHYDROPYRAN COMPOUND PRODUCED BY THE PRODUCTION PROCESS
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The invention provides a production process of a tetrahydropyran compound, characterized by allowing 3,4-dihydro-2-alkoxy-2H-pyran compound or tetrahydro-2-alkoxy-2H-pyran compound which can be easily prepared through reaction between acrolein and alkylvinylether, with hydrogen in the presence of a catalyst containing an element of Groups VIII to X under acidic condition. The production process of the invention is useful for production of Grignard reaction solvent or polymer solvent and intermediate of organic compound.
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Page/Page column 22
(2008/06/13)
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- Ring closure reactions of substituted 4-pentenyl-1-oxy radicals. The stereoselective synthesis of functionalized disubstituted tetrahydrofurans
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N-(Alkyloxy)pyridine-2(1H)-thiones 3 and benzenesulfenic acid O-esters 5 have been synthesized from substituted 4-pentenols 1 or the derived tosylates. Compounds 3 and 5 are efficient sources of free alkoxy radicals 6 which undergo synthetically useful fast ring closure reactions 6 → 8 [k(exo) = (2 ± 1) x 108 s-1 to (6 ± 2) x 109 s-1 (T = 30 ± 0.2°C)]. Tetrahydrofurfuryl radicals 8 can be trapped with, e.g., hydrogen or chlorine atom donors to afford either trans- or cis-disubstituted tetrahydrofurans 10 or 12 depending on the substitution pattern of the 4-pentenyloxy radical. Substituted tetrahydropyrans 11 or 13 are formed in the minor 6-endo-trig cyclization. According to the data of competition kinetics, the observed stereoselectivities in free alkoxy radical cyclizations arise from steric interactions between the substituents in the transition state of the ring closure reactions. Alkyl substituents cause small differences in the measured relative rate constants of 5-exo cyclizations which are reminiscent of the data obtained from the rearrangements of alkyl-substituted 5-hexenyl radicals. Likewise, a stereochemical model for oxygen radical cyclization is proposed where the pentenyloxy chain adopts a six-membered, chairlike transition state with the alkyl substituents preferentially situated in the pseudoequatorial positions leading to 2,5-trans-, 2,4-cis-, and 2,3-trans-substituted tetrahydrofurfuryl radicals 8 as the major intermediates.
- Hartung,Gallou
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p. 6706 - 6716
(2007/10/03)
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- EXPERIMENTAL STUDIES OF THE ANOMERIC EFFECT. PART I. 2-SUBSTITUTED TETRAHYDROPYRANS.
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Variable temperature (1)H and (13)C n.m.r. studies in CFCl3/CDCl3 of equilibria in 2-substituted- and 2-substituted-4-methyl-tetrahydropyranes have given conformational enthalpy differences and conformational entropy differences for chloro, methoxy, hydroxy and methylamino substituents.For ΔHoa->e, the values obtained, in kcal /mol, were 1.67 (Cl), 0.03 (OCH3), -0.63 (OH) and -1.75 (NHCH3); for ΔSoa->e the values obtained, in cal K-1mol-1 were -1.69 (Cl), -2.52 (OCH3), -2.50 (OH) and -0.60 (NHCH3).The trend in ΔHo values confirms the importance of antiperiplanar n-?* stabilisation as a contributor to the explanation of the anomeric effect, and supports a suggestion that endo- and exo-anomeric effects which occur in the same conformation are competitive.A variable temperature (13)C n.m.r. study of (Me-(13)C)-4-methyl-tetrahydropyran in CD2Cl2 has given a conformational enthalpy difference (ΔHoa->e) of -1.86 kcal/mol and a conformational entropy difference (ΔSoa->e) of -0.07 cal K-1mol-1 for a methyl substituent at the 4-position of a tetrahydropyran.
- Booth, Harold,Kheidhair, Kheidhair A.,Readshaw, Simon A.
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p. 4699 - 4724
(2007/10/02)
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- ALUMINIUM CHLORIDE IN THE IONIC HYDROGENATION OF OXYGEN-CONTAINING COMPOUNDS OF VARIOUS CLASSES
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The ionic hydrogenation of alcohols, ketones, and ketals was realized with triethylsilane in the presence of aluminium chloride.Gaseous hydrogen chloride was used as proton donor during the hydrogenation of the alcohols and ketones.It was established that, depending on the relative amount of aluminium chloride, hydrogenation can be realized with retention of the selectivity exhibited with the triethylsilane-trifluoroacetic acid pair as hydrogenating agent, and the applicability limits of ionic hydrogenation can be extended.The ionic hydrogenation of derivatives of di- and tetrahydropyran was realized for the first time, and the effect of the substrate structure on the reaction was established.
- Kursanov, D. N.,Bolestova, G. I.,Ibatullin, U. G.,Kuramshina, E. A.,Parnes, Z. N.
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p. 2078 - 2085
(2007/10/02)
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- Carbon-13 NMR Spectra of Saturated Heterocycles. XI - Tetrahydropyrans (Oxanes)
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The 13C NMR spectra of 62 oxanes (tetrahydropyrans) with and without methyl substituents at various ring positions, some of them bearing in addition (or instead) ethyl, vinyl, ethynyl, carbomethoxy and methylol substituents at C-2, have been recorded, and the 294 resulting chemical shifts have been correlated by multiple linear regression analysis.Axial and equatorial α-, β-, γ-, δ-, gem- and vic-parameters for shifts caused by methyl groups at all ring positions, and similar parameters for Et, -CH=CH2, -CCH, CO2Me and CH2OH groups at C-2, are reported.Standard deviations of the parameters are, in most cases, within 0.3 ppm and the agreement of calculated and experimental shifts is excellent.This is probably the largest parameter set of this type extant. 13C NMR spectra of a number of additional substituted tetrahydropyrans, and of 3,6-dihydro-2H-pyrans and 3,4-dihydro-2H-pyrans, are tabulated and discussed.
- Eliel, Ernest L.,Manoharan, Muthiah,Pietrusiewicz, K. Michal,Hargrave, Karl D.
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