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Tetrahydrofuran Derivatives (tetrahydrofuran + derivative)
Selected AbstractsCascade Reactions: Catalytic Synthesis of Functionalized 1,3-Dihydroisobenzofuran and Tetrahydrofuran Derivatives by Sequential Nucleophilic Ring Opening,Heterocyclization, Oxidative Carbonylation of AlkynyloxiranesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Nicola Della Ca' Abstract Differently substituted alkynyloxiranes were efficiently converted into functionalized 1,3-dihydroisobenzofurans and tetrahydrofuran derivatives in fair to good yields by a new cascade reaction, consisting of a sequential nucleophilic ring opening,heterocyclization,oxidative carbonylation process. Reactions were carried out at 80,100,°C and under a 3:1 mixture of carbon monoxide and air (total pressure=32,42,atm at 25,°C) in methanol or acetonitrile/methanol mixtures in the presence of catalytic amounts of palladium diiodide in conjunction with an excess of potassium iodide. The nucleophilic species beginning the cascade process by regioselective attack to the less hindered carbon of the oxirane ring can be methanol itself or iodide anions. [source] ChemInform Abstract: Cascade Reactions: Catalytic Synthesis of Functionalized 1,3-Dihydroisobenzofuran and Tetrahydrofuran Derivatives by Sequential Nucleophilic Ring-Opening,Heterocyclization,Oxidative Carbonylation of Alkynyloxiranes.CHEMINFORM, Issue 9 2010Nicola Della Ca' Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Fluoroalkylation of Pent-4-en-1-ols Initiated by Sodium Dithionite to Synthesize Fluorine-Containing Tetrahydrofuran Derivatives.CHEMINFORM, Issue 52 2007Yueyan Yang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] ChemInform Abstract: Oxidative Cyclization of Cinnamyl Ethers Mediated by CAN: A Stereoselective Synthesis of 3,4-trans Disubstituted Tetrahydrofuran Derivatives.CHEMINFORM, Issue 52 2001Vijay Nair Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Reaction of Homoallylic Alcohols with NaIO4/NaHSO3 Reagent,Synthesis of Alkyl-Substituted Tetrahydrofuran Derivatives.CHEMINFORM, Issue 15 2001Yoshio Okimoto Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] On the Scope of a Prins -Type Cyclization of Oxonium IonsHELVETICA CHIMICA ACTA, Issue 11 2004Georg Fráter The Prins cyclization of an aldehyde 1 with a homoallylic alcohol 2, affording tetrahydro-2H -pyrans 4via the oxonium ion 3 as central intermediate, was conceptually transferred to (alk-3-enyloxy)acrylates 6, which form a related oxonium ion 7 upon treatment with acids (Scheme,1). The scope and utility of this modification of the Prins -type cyclization of oxonium ions is discussed exemplarily by means of the syntheses of ten tetrahydro-2H -pyran and tetrahydrofuran derivatives, featuring diverse substitution patterns as well as different degrees of molecular complexity. These target structures include (±)-ethyl (2RS)-2-[(2RS,4SR,6RS)- and (2SR,4RS,6SR)-2-tetahydro-4-hydroxy-6-methylpyran-2-yl]propanoate (23), (±)-ethyl [(2RS, 3RS)-tetrahydro-3-isopropenylfuran-2-yl]acetate (32), (±)-ethyl (2Z)-3-(tetrahydro-2,2-dimethylfuran-3-yl)acrylate (37), (±)-(3aRS,6RS, 7aRS)-octahydro-7a-methylbenzofuran-6-yl formate (42), (±)-ethyl (2RS,3RS,4aRS,8SR,8aRS)-hexahydro-2,5,5,8-tetramethyl-7-oxo-2H,5H -pyrano[4,3- b]pyran-3-carboxylate (48), and (±)-ethyl (2RS,3RS,6SR)-tetrahydro-6-(2-methoxy-2-oxoethyl)-3-methyl-2H -pyran-2-carboxylate (53) (see Schemes,3 and 5,8). Besides the stereochemistry and mechanistic details of this versatile oxonium-ion cyclization, the synthesis of suitable starting materials is also described. [source] Cascade Reactions: Catalytic Synthesis of Functionalized 1,3-Dihydroisobenzofuran and Tetrahydrofuran Derivatives by Sequential Nucleophilic Ring Opening,Heterocyclization, Oxidative Carbonylation of AlkynyloxiranesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Nicola Della Ca' Abstract Differently substituted alkynyloxiranes were efficiently converted into functionalized 1,3-dihydroisobenzofurans and tetrahydrofuran derivatives in fair to good yields by a new cascade reaction, consisting of a sequential nucleophilic ring opening,heterocyclization,oxidative carbonylation process. Reactions were carried out at 80,100,°C and under a 3:1 mixture of carbon monoxide and air (total pressure=32,42,atm at 25,°C) in methanol or acetonitrile/methanol mixtures in the presence of catalytic amounts of palladium diiodide in conjunction with an excess of potassium iodide. The nucleophilic species beginning the cascade process by regioselective attack to the less hindered carbon of the oxirane ring can be methanol itself or iodide anions. [source] 1H and 13C chemical shifts for some tetrasubstituted 2,5-diaryl di- and tetrahydrofuran derivativesMAGNETIC RESONANCE IN CHEMISTRY, Issue 2 2007S. Martinet Abstract The 1H and 13C NMR chemical shifts of four 2,5-diaryltetrahydrofuran derivatives and their dihydro precursors were assigned completely with certainty using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC) Copyright © 2006 John Wiley & Sons, Ltd. [source] Biocatalytic Asymmetric Rearrangement of a Methylene-Interrupted Bis-epoxide: Simultaneous Control of Four Asymmetric Centers Through a Biomimetic Reaction CascadeCHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2004Silvia M. Glueck Abstract Asymmetric enzyme-catalyzed hydrolysis of methylene-interrupted bis-epoxides 1,a and 1,b catalyzed by bacterial epoxide hydrolases furnished tetrahydrofuran derivatives 2,a and 2,b through a hydrolysis,rearrangement cascade. Whereas racemic bis-oxiranes 1,b,d underwent kinetic resolution with moderate stereoselectivities to yield products with up to 92,% ee and 66,% de: meso -bis-oxirane cis,cis- 1,a was transformed into (6R,7R,9S,10S)- 2,a in 94,% ee and 89,% de at high conversion (85,%) by Rhodococcus sp. CBS 717.73 as the major product. The reaction sequence resembles a biomimetic reaction cascade and provides an efficient entry into the structural core of annonaceous acetogenins with simultaneous control of four stereocenters. 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