• Title/Summary/Keyword: dihydrofuran

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Stereoselective Synthesis of Farnesol (Farnesol의 입체선택적 합성)

  • Dong-Soo Shin
    • Journal of the Korean Chemical Society
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    • v.36 no.4
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    • pp.579-583
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    • 1992
  • Stereoselective synthesis of farnesol, (2E, 6E)-3,7,11-trimethyldodeca-2,6,10-tiren-1-ol(1), was carried out using 5-bromo-2-methylpent-2-ene(2) as a starting material. After conversion of 5-bromo-2-methylpent-2-ene(2) to the corresponding iodide compound, 5-(4-methylpent-3-enyl)-2,3-dihydrofuran(4) was obtained by alkylation of 5-lithio-2,3-dihydrofuran with 5-iodo-2-methylpent-2-ene. Ni(0)-catalyzed coupling reaction of the dihydrofuran 4 with MeMgI was proceeded to give (3E)-4,8-dimethylnona-3,7-dien-1-ol(5) in 72% yield. The resultant homoallylic alcohol 5 was converted to the (5E)-6,10-dimethylundeca-5,9-dien-2-one(8) in 4 steps. Compound 8 was condensed with dimethylmethoxycarbonylmethylphosponate in benzene follwed by $NaBH_4$ reduction in EtOH to yield (2E, 6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-ol(1). Ni(0)-catalyzed coupling reaction of MeMgI with dihydrofuran 4 was a key step in this synthesis of farnesol(1).

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Synthesis of Alternating Head-to-Head Copolymer of Methyl $\alpha$-cyanoacrylate and 2,3-Dihydrofuran. Ring-Opening Polymerization of 3-Methoxy-4-cyano-2,9-dioxabicyclo[4.3.0]non-3-ene

  • Lee, Ju-Yeon;Cho, I-Whan
    • Bulletin of the Korean Chemical Society
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    • v.9 no.3
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    • pp.176-179
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    • 1988
  • 3-Methoxy-4-cyano-2,9-dioxabicyclo[4.3.0]non-3-e ne (1) was prepared by (4 + 2) cycloaddition reaction of methyl ${\alpha}$-cyanoacrylate with 2,3-dihydrofuran. Compound 1 was ring-open polymerized by cationic catalyst such as boron trifluoride etherate to obtain alternating head-to-head (H-H) copolymer (2) of methyl $\alpha$ -cyanoacrylate and 2,3-dihydrofuran. For comparison, head-to-tail (H-T) copolymer (3) was also prepared by free radical copolymerization of the corresponding monomers. The H-H copolymer exhibited minor differences in its $^1H$-NMR and IR spectra, but in the $^{13}C$-NMR spectra significant differences were observed between the H-H and H-T copolymers. All of the H-H and H-T copolymers were soluble in common solvents and the inherent viscosities were in the range 0.2-0.3 dl/g.

Synthesis of Spiroannulated Dihydrofuran Compounds Utilizing Cerium(IV) Ammonium Nitrate (Cerium(IV) Ammonium Nitrate를 이용한 Spiroannulated 다이하이드로퓨란 화합물의 합성)

  • Kim, Byung-SO
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.4
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    • pp.385-390
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    • 2002
  • An efficient synthesis of spiroannulated dihydrofurans is achieved from 1,3-dicarbonyl compounds and exocyclic alkenes in the presence of cerium ammonium nitrate(IV) in moderate yields. In the case of entries 3-9, as a single product was seen. Especially, reaction of 15 with methylenecyclohexane afforded the two regioisomeric cyclo adducts 21 and 22. The structures of these adducts were confirmed by IR and NMR-Spectra.

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Component Analysis of Softwood Vinegar (침엽수 목초액의 성분분석)

  • ;;;Sano Yoshihiro
    • Journal of Korea Foresty Energy
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    • v.20 no.1
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    • pp.28-34
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    • 2001
  • To analyze chemical compositions of softwood vinegar prepared with continuous carbonized kiln, the chemical compositions were analyzed by GC-MS spectrometry. The results were summarized as follow : 1. The amounts of methylalcohol and acetic acid and of vinegar were 0.12% and 0.8% respectively, and acidity was 0.85 2. Perfume components of vinegar were frufual, 5-meayl-2-furancarboxyaldehyde, 2,3-pentanedione, 2-butanol, 2,3-dihydrofuran, 1-(2-furanyl)-etanone, benzaldehyde, 2-furan carboxyaldehyde and acetic acid. 3 Vinegar prepared from softwood, so that murk amount of guaiacyl compound and phenol derivetives are produced from lignin and extractives was analγzed. 4 The yield of 4-methyl-di-tert-butylphenol was the highest in the nutural and carbonyl and acetic acid in the acid fractions, 3-ethylpentane in the basic fraction, and guaiacol in the phenolic fraction.

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AgBF4/[Bmim]BF4-Catalyzed [3+2] Cycloaddition of Cyclic Diazodicarbonyl Compounds: Efficient Synthesis of 2,3-Dihydrofurans and Conversion to 3-Acylfurans

  • Xia, Likai;Lee, Yong-Rok;Kim, Sung-Hong;Lyoo, Won-Seok
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1554-1558
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    • 2011
  • A novel and efficient method for the synthesis of 2,3-dihydrofurans bearing a variety of substituents on the dihydrofuran ring was achieved by the reaction of cyclic diazodicarbonyl compounds with styrene and vinyl acetate. The key strategy was AgBF$_4$/[Bmim]BF$_4$-catalyzed [3+2] cycloaddition. The synthesized dihydrofurans with an acetate group were further converted to the corresponding 3-acylfurans.

Synthesis of 1,2,3,4-Tetrahydroquinolines Using AlCl3 in Aqua Mediated

  • Behbahani, Farahnaz K.;Ziaei, Parisa
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.44-48
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    • 2014
  • Catalytic performance of Lewis acids have been investigated in the synthesis of 1,2,3,4-tetrahydroquinolines via cyclocondensation reaction of aniline derivatives with cyclic enol ethers such as 3,4-dihydro-2H-pyran and 2,3-dihydrofuran. The catalytic activity of various of these catalysts in different solvents was compared with other classical catalysts such as KSF clay (1.5 g), $InCl_3$ (10-20 mol%), $ZrOCl_2$ (10 mol%), $Sc(OTf)_3$ (3 mol%), PANI-$InCl_3$ (10 mol%), $I_2$ (20 mol%), $InCl_3$ (5 mol%), 4-npa (25 mol%) and Cellulose-$SO_3H$ (0.03 g).