16014-91-8

Upstream product

• 102632-99-5 1-phenyl-4-penten-1-ol 
• 97-99-4 Tetrahydrofurfuryl alcohol 
• 259874-44-7 5-(benzyldimethylsilyl)-1-(tetrahydropyran-2′-yloxy)pent-4-yne 
• 320400-37-1 (Z)-5-dimethylsilyl-4-penten-1-ol 
• 259874-48-1 (Z)-5-benzyldimethylsilyl-4-pentenal 
• 320399-96-0 5-dimethylsilyl-1-(2-tetrahydropyranyloxy)-4-pentyne 
• 62992-46-5 1-(tetrahydropyranyloxy)-4-pentyn 
• 5390-04-5 pent-1-yn-5-ol 
• 174503-81-2 (Z)-5-dimethylsilyl-1-phenyl-4-penten-1-ol 
• 259874-46-9 (Z)-5-benzyldimethylsilyl-4-penten-1-ol 
• 259874-54-9 (Z)-5-benzyldimethylsilyl-1-phenyl-4-penten-1-ol 
• 67-63-0 isopropyl alcohol 
• 98-86-2 acetophenone 
• 22078-90-6 2-hydroxymethyl-5-phenylfuran 

Downstream Products

• 1080500-21-5 tetrahydro-5-phenylfur-2-ylcarbaldehyde 
• 93202-17-6 2-Ethoxymethyl-5-phenyl-tetrahydro-furan 

Relevant academic research and scientific papers

Acid-catalyzed cyclization of vinylsilanes bearing a hydroxy group. Benzyldimethylsilyl group as an effective promoter and novel hydroxy surrogate

A benzyldimethylsilyl (BnDMS) group was found to effectively enhance the reactivity of vinylsilanes toward the acid-catalyzed intramolecular addition of a hydroxy group in comparison with a dimethylphenylsilyl group. The BnDMS group of the resultant cyclized products could be easily converted to a hydroxy group by the action of TBAF-H2O2-KHCO3. (C) 2000 Elsevier Science Ltd.

Stereoselective synthesis of 2,5-disubstituted tetrahydrofurans by silicon-directed cyclization of vinylsilanes bearing a hydroxy group

In the presence of a catalytic amount of p-toluenesulfonic acid (TsOH) or TiCl4, (Z)-1-substituted-5-silyl-4-penten-1-ols can be easily transformed into 2,5-disubstituted tetrahydrofurans with high trans-selectivities.

Lewis Acid Mediated "endo-dig" Hydroalkoxylation-Reduction on Internal Alkynols for the Stereoselective Synthesis of Cyclic Ethers and 1,4-Oxazepanes

Lewis acid mediated 5/6/7-endo-dig hydroalkoxylation-reduction cascade on internal alkynols gave an expedient, stereoselective synthesis of cyclic ethers and 1,4-oxazepanes. The strategy has been extended to the first examples of hydroalkoxylation-alkyne

Organocatalytic synthesis of polysubstituted tetrahydrofurans from alkenes

A novel, organocatalytic and environmentally friendly protocol for the synthesis of polysubstituted tetrahydrofurans from trivial starting materials has been described. By employing 2,2,2-trifluoroacetophenone-mediated oxidation, which utilizes H2O2 as a green oxidant, we introduce a sustainable procedure that embraces the principles of green chemistry for the production of substituted tetrahydrofurans in high to excellent yields and tolerates a wide range of substitution patterns.

Activating tert-butyl hydroperoxide by chelated vanadates for stereoselectively preparing sidechain-functionalized tetrahydrofurans

tert-Butyl hydroperoxide (TBHP) stereoselectively oxidizes substituted 4-pentenols, when activated by (ethyl)[cis-(piperidine-2,6-diyl)dimethyl] vanadates. The reaction affords (tetrahydrofuran-2-yl)methanols in up to 89% yield, and in stereoselectivity r

Formation of 3-acyloxy-γ-butyrolactones from 4-pentenols in vanadium-catalyzed oxidations

O-Acyl derivatives of 3-hydroxy-γ-butyrolactone are formed in up to 20% yield as by-products from 1-alkyl- and 1-phenyl-substituted 4-pentenols and tert-butyl hydroperoxide (TBHP) in vanadium-catalyzed synthesis of (tetrahydrofuran-2-yl)-methanols. The lactones are secondary products formed from (tetrahydrofuran-2-yl)-methanols via hydrogen atom abstraction in positions 4 and 5, as derived from experiments starting from deuterium-labeled alkenols. Stereocenters at tetrahydrofuran carbon 2 and the proximate hydroxyl carbon of the alkanol side chain retain configuration in the course of oxidative tetrahydrofuran conversion. In an atmosphere of nitrogen or argon, no γ-butyrolactone formation occurs, pointing to dioxygen as terminal oxidant for the secondary oxidation. Adding cyclohexa-1,4-diene or γ-terpinene to a solution of a 4-pentenol, TBHP, and a vanadium catalyst exposed to air inhibits formation of γ-butyrolactones. A third approach to prevent γ-butyrolactones from being formed in oxidative 4-pentenol cyclization uses cis-2,6-bis-(methanol)-piperidine instead of N-salicylidene-ortho-aminophenol as tridentate auxiliary for the vanadium catalyst.

Effective synthesis of 2,5-disubstituted tetrahydrofurans from glycerol by catalytic alkylation of ketones

The [IrCl(cod)]2 catalyzed α-alkylation of substituted acetophenones with solketal followed by reduction and iron mediated cyclization provides 2,5-disubstituted tetrahydrofurans.

Increased yields and simplified purification with a second-generation cobalt catalyst for the oxidative formation of trans-THF rings

[Chemical Equation Presented] The synthesis of a second-generation cobalt catalyst for the formation of trans-THF products via the Mukalyama aerobic oxidative cycllzation is reported. Two procedures have been developed with the new water-soluble catalyst

Activation of molecular oxygen and its use in stereoselective tetrahydrofuran-syntheses from δ,ε-unsaturated alcohols

Bishomoallylic alcohols (pent-4-en-1-ols) underwent efficient oxidative cyclizations, if treated with O2 and bis{2,2,2-trifluoromethyl-1- [(1R,4S)-1,7,7-trimethyl-2-(oxo-κO)bicyclo[2.2.1]hept-3-yliden] ethanolato-κO}cobalt(ii) in solutions of 2-propanol at 60 °C. Ring closures occurred diastereoselectively and afforded 2,3-trans- (96% de), 2,4-cis- (～60% de), and 2,5-trans-substituted (>99% de) (phenyl)tetrahydrofur-2-ylmethanols as major components. Formation of bicyclic compounds and a 2,3,4,5-substituted oxolane was feasible as exemplified by syntheses of oxabicyclo[4.3.0]nonylmethanols and a derivative of natural product magnosalicin in 61-72% (90-99% de). The effectiveness of tetrahydrofuran synthesis was critically dependent on (i) solvent, (ii) reaction temperature, (iii) initial cobalt concentration, (iv) chain length between hydroxyl and vinyl groups, and (v) substitution at reacting entities. A sequence is proposed for rationalizing observed selectivities.

(Schiff-base)vanadium(v) complex-catalyzed oxidations of substituted bis(homoallylic) alcohols - Stereoselective synthesis of functionalized tetrahydrofurans

Vanadium(v) complexes 4 have been prepared from tridentate Schiff-base ligands 3 and VO(OEt)3. All vanadium(v) compounds were characterized (IR, UV/Vis, and 51V NMR spectroscopy, and in selected examples by X-ray diffraction analysis) and were applied as oxidation catalysts for the stereoselective synthesis of functionalized tetrahydrofurans 2 starting from substituted bis(homoallylic) alcohols 1 (mono- or trisubstituted C-C double bonds). Oxidation of secondary or tertiary 1-alkyl-, 1-vinyl-, or 1-phenyl-substituted 5,5-dimethyl-4-penten-1-ols under optimized conditions [TBHP as primary oxidant and 1,2-(amino)indanol-derived vanadium(v) reagent 4g as catalyst] provided 2,5-cis-configured tetrahydrofurans in synthetically useful yields and diastereoselectivities (22-96% de). On the other hand, trans-disubstituted oxolanes (62%-96 de) were obtained from oxidations of 2- or 3-alkyl- and 2- or 3-phenyl-substituted 5,5-dimethyl-4-penten-1-ols bis(homoallylic) allyhc) alcohols. Treatment of 4-penten-1-ols (i.e. substrates with monosubstituted olefinic π-bonds) with TBHP and catalytic amounts of vanadium(v) complex 4g furnished trans-disubstituted tetrahydrofurans as major products (20-96% de), no matter whether an alkyl or a phenyl substituent was located in position 1, 2, or 3 of the alkenol chain. The mechanism of this reaction has been investigated in detail. Based on results from 51V NMR spectroscopy and competition kinetics, it proceeds by a transition metal-peroxy pathway. In an initial step, TBHP coordinates to, for example, N-(2-oxidophenyl)salicylideniminato-derived vanadium complex 4a. Subsequent alkenol binding gives rise to a "loaded" vanadium(v) peroxy complex (e.g. 60) which facilitates diastereoselective oxygen transfer, presumably onto a coordinated substrate. This step leads to the formation of functionalized tetrahydrofurans as major products. TBHP binding to the remaining vanadium(v) complex then allows a regeneration of the active oxidant, for example peroxy complex 57. The origin of the observed diastereoselectivity in this oxidation has been studied in an independent stereochemical analysis. Thus, diastereomerically enriched epoxy alcohol (1R,4R)-10 was prepared. Its treatment with 1,2-(amino)indanol-derived vanadium complex 4g affords a 91:9 mixture of cis-2-(1-hydroxy-1-methylethyl)-5-(phenyl)tetrahydrofuran (cis-6) and cis-2,2-dimethyl-6-(phenyl)tetrahydropyran-3-ol (cis-7). Similarly, a 39:61 mixture of heterocycles trans-6 and trans-7 was obtained from epoxy alcohol (1S,4R)-10, if treated with Lewis acid 4g. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).