- Solid acid-catalyzed conversion of furfuryl alcohol to alkyl tetrahydrofurfuryl ether
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The acidic zeolite HZSM-5 (Si/Al = 25) achieved 58.9% selectivity of methyl furfuryl ether (MFE) and 44.8% selectivity of ethyl furfuryl ether (EFE) from etherification of furfuryl alcohol with methanol and ethanol. MFE and EFE were quantitatively hydrogenated into methyl tetrahydrofurfuryl ether (MTE) and ethyl tetrahydrofurfuryl ether (ETE) using a Raney Ni catalyst.
- Cao, Quan,Guan, Jing,Peng, Gongming,Hou, Tonggang,Zhou, Jianwei,Mu, Xindong
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- New Conversion of Esters to Ethers and Its Application to the Preparation of Furano-18-crown-6
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Thionoesters which are readily prepared from esters can be desulfurized with Raney nickel to form the corresponding ethers.This new synthetic pathway to convert esters to ethers avoids many of the steric and functional limitations of known methods and appears to be a general method for this conversion.
- Baxter, Steven L.,Bradshaw, Jerald S.
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- Utilization of renewable resources: Investigation on role of active sites in zeolite catalyst for transformation of furfuryl alcohol into alkyl levulinate
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A bio-derived furfuryl alcohol transformation into various high-value chemicals is a growing field of interest among researchers. This study reports an exclusive investigation of the porosity and active sites responsible for the efficient alcoholysis of furfuryl alcohol to alkyl levulinate by the aid of zeolite catalyst. Alkyl levulinate is a promising platform chemical potentially used as a fuel additive and also for the production of chemicals. A detailed study using well-characterized HZSM-5 catalyst on the influence of acidity and post synthesis modification like desilication, dealumination, metal ion exchange and phosphate modification revealed the most desired type of acid sites required to catalyze this reaction. Among the HZSM-5 catalysts tested, HZSM-5 (SAR 95) showed the best performance of ≥ 99 % furfuryl alcohol conversion and 85 % butyl levulinate selectivity under optimum conditions. The catalyst exhibited good recyclability additionally addressing all the challenges reported in the previous literature fulfilling the green chemistry principles.
- Vaishnavi,Sujith,Kulal, Nagendra,Manjunathan, Pandian,Shanbhag, Ganapati V.
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- Synthesis of phenylthiomethyl substituted furans by Lewis acid catalysed substitution
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Two routes to the differentially functionalised trisubstituted furan methyl 4-methyl-2-[(phenylthio)methyl]-3-furoate are presented. One is a direct palladium catalysed annulation which proceeds smoothly in the presence of a thioether and the other depends on a highly chemoselective displacement of a methoxy group by phenylthiotrimethylsilane. The scope and mechanism of the latter transformation was probed with simple model systems.
- Greeves,Torode
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- Conformational Analysis of Furyl- and Thienylhydroxymethyl Radicals
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Low-temperature photolysis of ArCH2OH derivatives (Ar = 2- and 3-furyl and -thienyl) in the presence of ButOOBut yields the corresponding ArCHOH radicals which can be observed by means of EPR spectroscopy.Each radical displays E and Z rotational conformers due to restricted Ar-Cα rotation.The study of ArCHOMe radicals, as well as of 2-furyl- and 2-thienylhydroxymethyl radicals having a methyl group in position 3 of the ring, allowed us to identify the most stable of the two conformers.The temperature dependence of the αOH hfs constant (assigned by deuterium substitution) has been interpreted on the basis of an averaging of ab initio αOH hfs constant over the rotation about the Cα-O bond which also allowed us to obtain an estimate of the corresponding rotation barrier.
- Cremonini, Mauro A.,Lunazzi, Lodovico,Placucci, Giuseppe
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- Microwave-assisted catalytic upgrading of bio-based furfuryl alcohol to alkyl levulinate over commercial non-metal activated carbon
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A cheap and commercially available non-metal activated carbon (AC) as an efficient catalyst for the alcoholysis of furfuryl alcohol (FA) to alkyl levulinate (AL) under microwave assistance was firstly investigated. The catalyst gave an impressive methyl levulinate (ML) yield of 78% in only 5 min at 170 °C in the presence of FA (0.2 M, 3 mL) and AC (100 mg). Various reaction parameters in dependence of time such as temperature, catalyst and feedstock loadings as well as solvent types have been optimized. The re-utilization experiments of the catalyst showed that the activity related to the acidic groups of the catalysts, and the deactivation was due to the leaching of acidic specie, which was easily extracted by the solvent. Note that extremely low concentration of the active species extracted from AC (less than 1 wt %) could also give 62% ML yield. The present study provided a promising way for AL synthesis over cheap, commercially available and environmentally benign catalyst.
- Wang, Yantao,Zhao, Deyang,Triantafyllidis, Konstantinos S.,Ouyang, Weiyi,Luque, Rafael,Len, Christophe
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- METAL-IODIDE CATALYTIC SYSTEM FOR DIRECT ETHERIFICATION FROM ALDEHYDES AND/OR KETONES
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A process for etherification of aldehydes and/or ketones in the presence of a catalyst and an iodine source.
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Page/Page column 13; 14; 15
(2020/01/24)
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- Facile synthesis of furfuryl ethyl ether in high yield: Via the reductive etherification of furfural in ethanol over Pd/C under mild conditions
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The one-pot synthesis of furfuryl ethyl ether (FEE) over Pd nanoparticles supported on TiO2, Al2O3, SiO2, and active carbon via the catalytic reductive etherification of furfural in ethanol was systematically studied. The Pd nanoparticles supported on SiO2, TiO2 and active carbon are all active for this novel process under mild reaction conditions, with Pd/C showing the highest selectivity to FEE. The effects of palladium loading, reaction temperature, and hydrogen pressure on the activity and selectivity of Pd/C have been investigated in detail. The results demonstrate that suitable Pd amount, low reaction temperature of about 60 °C, and low H2 pressure of about 0.3 MPa are favorable for the formation of the desired ether product. Under the optimized conditions, an unprecedented high yield of up to 81% of FEE was firstly obtained with the major by-products being furfuryl alcohol and 2-methyltetrahydrofuran. Compared with the conventional hydrogenation-etherification route via furfural alcohol as a reaction intermediate, the reductive etherification shows significant advantage in product yield because of its much lower reaction temperature that is required.
- Wang, Yun,Cui, Qianqian,Guan, Yejun,Wu, Peng
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supporting information
p. 2110 - 2117
(2018/05/24)
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- Catalytic upgrading of furfuryl alcohol to bio-products: Catalysts screening and kinetic analysis
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The conversion of furfuryl alcohol, a highly versatile biomass-derived platform molecule, into a large variety of bio-products, including ethers, lactones and levulinates, has been evaluated in alcohol media using different solid acid catalysts, such as commercial zeolites, sulfonic acid-functionalized materials, and sulfated zirconia. Reaction pathways and mechanisms have been correlated to the particular type of catalyst used, aiming to establish the influence of the main physico-chemical properties of the materials on the extent of furfuryl alcohol conversion, as well as on the predominant reaction pathway followed. Mechanistic and kinetics modelling studies for each type of catalyst have been developed and compared, providing an useful tool for the selection of the most suitable solid acid catalyst for the production of each of the reaction intermediates in the cascade from furfuryl alcohol to alkyl levulinate.
- Paniagua,Melero,Iglesias,Morales,Hernández,López-Aguado
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- Preparation method for furfuryl alkyl ether
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The invention discloses a preparation method for furfuryl alkyl ether through reaction of furfuryl alcohol and monohydric alcohol. The preparation method comprises the following steps: dissolving furfuryl alcohol in monohydric alcohol in a reaction kettle; then adding a catalyst; and next carrying out a reaction for 1-24 hours at the temperature of 150-260 DEG C, and thus obtaining the furfuryl alkyl ether. The preparation method is simple in process and easy to control, only adopts an inorganic metal oxide as the catalyst, has no addition of organic acids and alkalis, inorganic acids and alkalis or other co-catalysts, is convenient for separation of the catalyst and other operations, and is conducive to large-scale industrialized production.
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Paragraph 0022-0023
(2017/06/10)
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- Upgrading biomass-derived furans via acid-catalysis/hydrogenation: The remarkable difference between water and methanol as the solvent
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In methanol 5-hydroxymethylfurfural (HMF) and furfuryl alcohol (FA) can be selectively converted into methyl levulinate via acidcatalysis, whereas in water polymerization dominates. The hydrogenation of HMF, furan and furfural with the exception of FA is
- Hu, Xun,Westerhof, Roel J. M.,Wu, Liping,Dong, Dehua,Li, Chun-Zhu
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p. 219 - 224
(2018/04/16)
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- Indium(III) triflate promoted synthesis of alkyl levulinates from furyl alcohols and furyl aldehydes
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A facile protocol for the alcoholysis of furfuryl alcohol into levulinate esters has been developed employing low catalyst loadings of indium(III) triflate. This method provides a rapid and efficient route for the synthesis of these useful materials. The alcoholysis reactions of 5-hydroxymethylfurfural (HMF), furfural and furfural dimethylacetal were also investigated under these reaction conditions.
- Kean, Jacqueline R.,Graham, Andrew E.
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p. 175 - 179
(2015/02/19)
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- Palladium-catalyzed C-H homocoupling of furans and thiophenes using oxygen as the oxidant
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A general and efficient palladium-catalyzed intermolecular direct C-H homocoupling of furans and thiophenes has been developed. The reaction is characterized by using molecular oxygen as the sole oxidant and complete C5-position regioselectivity. Both C2- and C3-substituted furans or thiophenes are appropriate substrates. The approach provides a straightforward, facile, and economical route to bifurans and bithiophenes under mild reaction conditions.
- Li, Na-Na,Zhang, Yan-Lei,Mao, Shuai,Gao, Ya-Ru,Guo, Dong-Dong,Wang, Yong-Qiang
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supporting information
p. 2732 - 2735
(2014/06/09)
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- Iridium-catalyzed oxidative olefination of furans with unactivated alkenes
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The oxidative coupling of arenes and alkenes is an attractive strategy for the synthesis of vinylarenes, but reactions with unactivated alkenes have typically occurred in low yield. We report an Ir-catalyzed oxidative coupling of furans with unactivated olefins to generate branched vinylfuran products in high yields and with high selectivities with a second alkene as the hydrogen acceptor. Detailed mechanistic experiments revealed catalyst decomposition pathways that were alleviated by the judicious selection of reaction conditions and application of new ligands.
- Sevov, Christo S.,Hartwig, John F.
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supporting information
p. 10625 - 10631
(2014/08/18)
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- Single pot conversion of furfuryl alcohol to levulinic esters and γ-valerolactone in the presence of sulfonic acid functionalized ILs and metal catalysts
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Ionic liquids functionalized with acidic anions, HSO4, ClSO 3H, PTSA, TFA (MIm), HSO4 and TFA (NMP) were found to efficiently (99% conversion) catalyze the alcoholysis of furfuryl alcohol (FAL) in the presence of methanol, ethanol, n-butanol and isopropyl alcohol (IPA) to the corresponding levulinic acid esters under mild temperature (90-130 °C) conditions. The extended alkyl chain length of [MIm] using 1,4-butane sultone enhanced the Bronsted acidity of [BMIm-SH][HSO4] catalyst resulting into the highest selectivity of >95% to Me-LA. An increase in both temperature and catalyst concentration increased the furfuryl alcohol conversion and selectivity to levulinate esters. In contrast, an increase in the substrate concentration from 5 to 15% caused a decrease in Me-LA selectivity due to accumulation of intermediate ethers of furfuryl alcohol. Using a combination of [BMIm-SH][HSO4] and 5% Ru/C catalyst, direct conversion of FAL to γ-valerolactone (GVL) is shown for the first time. A complete conversion of FAL with the highest selectivity of 68% to GVL could be achieved under optimum conditions while higher Ru loading enhanced the GVL selectivity to 94% in the hydrogenation step of this tandem approach. Our catalyst system could be efficiently recycled five times retaining the original activity and selectivity levels.
- Hengne, Amol M.,Kamble, Sumit B.,Rode, Chandrashekhar V.
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p. 2540 - 2547
(2013/09/12)
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- 5-SUBSTITUTED 2-(ALKOXYMETHYL)FURANS
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The present invention concerns a method for the manufacture of a 5-substituted 2- (alkoxymethyl)furan (or a mixture of such furans) by reacting a starting material comprising at least a 5-substituted furfural with hydrogen in the presence of an alcohol and a catalyst system
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Page/Page column 12-13
(2009/04/25)
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- Dearomatization of furans via [2,3]-Still-Wittig rearrangement
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Furans and benzofurans of type 1 were dearomatized via the [2,3]-Still-Wittig rearrangement. Enol ethers 2 could be isolated or isomerized to the corresponding furans 3. The substitution pattern at the homofuranylic position had a strong influence on reaction behavior. Benzofurans rearranged with the greatest efficiency, and employment of a 3-substituted benzofuran (1; R′=CH3) allowed the creation of a quaternary carbon center.
- Caruana, Patrick A.,Frontier, Alison J.
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p. 10921 - 10926
(2007/10/03)
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- Synthesis of angular quinoid heterocycles from 2-(2-nitrovinyl)-1,4- benzoquinone
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Reactions of 2-(2-nitrovinyl)-1,4-benzoquinone with furans, indoles, and endocyclic enol ethers form angular fused heterocyclic quinoid ring systems. The reaction proceeds by a formal inverse electron-demand [4 + 2] cycloaddition reaction of the nitrovinylquinone and a double bond of the heterocycle. The initial quinoid cycloadducts can be readily tautomerized to hydroquinoid species, which may be dehydrogenated to fully aromatic quinones. In the case of furans, the tautomerized adducts may be ring-opened to give 6,7-di- or 5,6,7-tri-substituted-1,4-naphthalenediols. In the case of endocyclic enol ethers, formation of benzofuran products competes with [4 + 2] cycloaddition.
- Noland, Wayland E.,Kedrowski, Brant L.
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p. 596 - 603
(2007/10/03)
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- Synthesis of alkyl heteryl ethers from acetates under interphase catalysis conditions in a liquid/solid system
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The reaction of acetates of heterocyclic alcohols with alkyl halides in the two-phase catalytic system of solid KOH/C6H6/18-crown-6 at room temperature leads selectively to the formation of the corresponding heterocyclic ethers in 32-93% yield. 1998 Plenum Publishing Corporation.
- Abele,Abele,Gaukhman,Lukevics
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- Cholinergic agents structurally related to furtrethonium. 1
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A series of 5-substituted-2-(dimethylaminomethyl)-furyl derivatives 4 was prepared, with the aim of discovering novel antimuscarinic agents which are selective for smooth muscle as opposed to cardiac tissue.Both non-quaternary and quaternary ammonium compounds were synthesised.The agonist starting point, furtrethonium 3, was gradually transformed into antagonist by introduction of lipophilic and bulky groups in position 5 of this molecule.In particular, the introduction of α-hydroxy-α-cyclohexylbenzyl moiety (compound 9b), a lipophilic group characteristic ofantimuscarinic agents, caused an appreciable increase of the antagonist's potency, and the lengthening of the distance between this lipophilic group and the furan ring, obtained by introduction of an ester, ether or amide group, led to some selectivity towards smooth muscle (compounds 19, 21, 25).Interestingly, compound 19, with an ester moiety as a spacer group, proved to be at least 20 times more potent in rat ileum (pKB = 7.3) and rat bladder (pKB = 7.2) than guinea-pig atria (pKB = 5.9). furtrethonium derivatives / cholinergic agents / antimuscarinic activity
- Manfredini, S.,Guarneri, M.,Simoni, D.,Grana, E.,Boselli, C.,et al.
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p. 153 - 162
(2007/10/02)
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- REACTION OF HALOMETHYLFURANS WITH SODIUM DIMETHYL PHOSPHITE AND TRIMETHYL PHOSPHITE
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Phosphorylation of 2- and 3-chloromethylfurans with sodium dimethyl phosphite in a methanol-benzene medium leads to formation of two products, a methoxy derivative and phosphonate, the first being predominant.Using sodium tert-butoxide as a metalating agent in benzene allows as to drive the process to the formation of phosphonates, but the yields are poor.Phase-transfer catalytic systems based on potassium hydroxide and fluoride are ineffective. 2- and 3-Mono and 2,3- and 2,5-bis(bromomethyl)furancarboxylates are phosphorylated with trimethyl phosphite under conditions of the Arbuzov reaction; however, in the presence of an additional acceptor substituent, such as an acetoxymethyl group, dehalogenation occurs.With 2,5-bis(halomethyl)-furan-3-carboxylates the Arbuzov reaction with trimethyl phosphite proceeds stepwise, the halomethyl group in position 5 reacting first, regardless of the halogen nature.The resulting intermediate products are not halomethyl phosphonates, which was proved by independent synthesis of the latter and by studying their chemical properties.
- Pevzner, L. M.,Ignat'ev, V. M.,Ionin, B. I.
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p. 1754 - 1763
(2007/10/03)
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- Pharmaceutically useful furyl substituted dihydroxyethylbutyrolactones
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The compounds 2-(5-methylthiomethyl-2-furyl)-2-hydroxy-3-keto-4- dihydroxyethylbutyrolactone and 2-(5-methoxymethyl-2- furyl)-2-furyl(-2-hydroxy-3-keto-4-dihydroxyethylbutyrolactone and pharmaceutical compositions containing them are useful to regulate the immune response in mammals.
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- Reactions of Carbenes with Oxetane and with Oxetane/ Methanol Mixtures
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Ethoxycarbonylcarbene, bis(methoxycarbonyl)carbene, phenylcarbene (17a), diphenylcarbene (17b), fluorenylidene (17c), 2-furylcarbene (31a), 2-furyl(phenyl)carbene (31b), 4-oxo-2,5-cyclohexadienylidene (40), and 4,4-dimethyl-2,5-cyclohexadienylidene (53) were generated by photolysis of the appropriate diazo compounds.With neat oxetane, most of these carbenes react by competitive C-H insertion (B -> A, Scheme 1) and ylide formation (B -> C). 31a and 40 do not insert into C-H bonds; 31b does not attack oxetane but rearranges exclusively with formation of 26.The ylides undergo Stevens rearrangement to give tetrahydrofurans (C -> D) and α',β-elimination, leading to allyl ethers (C -> E).With oxetane/ methanol mixtures, the intervention of oxonium ions (H) is indicated by the formation of 1,3-dialkoxypropanes (I).The oxonium ions arise either by protonation of the ylides (C -> H) or by protonation of the carbenes (B -> G), followed by electrophilic attack of the carbocations (G) at oxetane (G -> H).The former route is followed by the alkoxycarbonylcarbenes and by 40; the ylides derived from the remaining carbenes do not react with methanol, owing to their rapid Stevens rearrangements.Protonation of the carbenes 17b, 31, and 53 is clearly indicated by their product ratios and, for 31, by the formation of isomeric ethers (33, 36).The more electrophilic carbenes discriminate but slightly between oxetane and methanol while the more nucleophilic carbenes (17b, 31, 53) prefer the protic methanol strongly over the aprotic oxetane. Key Words: Carbenes/ Oxygen ylides/ Stevens rearrangement/ Oxonium ions/ Insertion, O-H/ Ylides
- Kirmse, Wolfgang,Lelgemann, Rudolf,Friedrich, Klaus
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p. 1853 - 1863
(2007/10/02)
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- Method of treating inflammation in mammals utilizing ketobutyrolactones and furylbutyrolactones
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Treatment of inflammation in mammals utilizing selected ketobutyrolactones and furylbutyrolactones. Treatment is applicable to both acute or chronic inflammation. Antiviral activity of methylfurylbutyrolactone is also disclosed.
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- Search for New Membrane-active Substances: Synthesis of Tropan-3-ols with Alkyl, Alkenyl and Alkenynyl Groups at the Bridgehead
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The synthesis of tropan-3-ols with alkyl, alkenyl and alkynyl groups at the bridgehead is described.The new compounds have been considered as new membrane-active substances that would serve as model compounds for histrionicotoxin (1).Application of the Noyori route to 2-substituted pyrroles was unsuccessful.In order to avoid difficulties in obtaining individual long-chain 4-keto aldehydes for the Robinson condensation of each new model compound a key tropane intermediate (8) was prepared instead.The first attempts to extend the chains of the mesyl ester of the diol (8b) and iodomethyltropanol (9b) by Grignard type coupling failed.Therefore we embarked on a Wittig reaction of the tropane-1-carbaldehyde (11) synthesized in high yield from the diol (8).Indeed, both pent-1-enyl- and pentyl-tropanols, (12) and (13) were obtained.Coupling with an acetylenic phosphorane led to the pent-1-enynyltropanol (14).A further new key compound, namely 3β-acetoxytropan-1-ylacetaldehyde (15) was also synthesized as a precursor to conjugated tropanyl enynes which would more closely resemble the natural product (1).
- Dharanipragada, Ramalinga,Fodor, Gabor
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p. 545 - 550
(2007/10/02)
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- Reactions in Slightly Hydrated Solid/Liquid Heterogeneous Media: The Methylation Reaction with Dimethyl Sulfoxide
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The O-methylation of alcohols and phenols with stoichiometric amounts of dimethyl sulfate in 1,4-dioxan or triglyme in the presence of solid potassium hydroxide and small amounts of water represents a useful method for the synthesis of methyl ethers in high yields and with high selectivity.The complete consumption of dimethyl sulfate in this reaction avoids the problems connected with the work-up of reaction mixtures still containing excess amounts of this toxic reagent.
- Achet, D.,Rocrelle, D.,Murengezi, I.,Delmas, M.,Gaset, A.
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p. 642 - 643
(2007/10/02)
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- 1-Substituted and 1,4-Disubstituted Tribenzocyclooctenes
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Diels-Alder cycloaddition between 5,6-didehydrodibenzocyclooctene and various furans leads to endoxides which are deoxygenated by low valent titanium to 1-substituted and 1,4-disubstituted tribenzocyclooctenes.Some chemical transformations of these new class of compounds are also reported.
- Wong, Henry N. C.,Xue Long Hou
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p. 1111 - 1115
(2007/10/02)
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