• Title/Summary/Keyword: 분자내 고리화반응

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Studies Towards Intramolecular Formal Iron-Catalyzed [4+2] Cycloaddition of Acetylenic Dienes (Fe(0) 촉매를 이용한 Acetylenic Dienes 의 분자내 [4+2] 고리화 첨가반응에 관한 연구)

  • Byeon, Sang Yong
    • Journal of the Korean Chemical Society
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    • v.38 no.1
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    • pp.61-68
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    • 1994

  • The intramolecular formal iron-catalyzed [4+2] cycloaddition reaction of acetylenic dienes to produce bicyclic products has been investigated. These reactions proceeded, competing via intramolecular carbocyclization and bimolecular cycloaddition. However, the iron-catalyzed bicyclic carbocyclization of 4,4-dimethyl-3-(tert-butyldimethylsiloxy)-1-phenyl-6,8-decadien-1-yne(11) yielded exclusively bicyclic diene product(yield 78.1%). From this result, we found that the substrate containing a dimethyl substitutent at the 4,4-position helped to promote the intramolecular reaction, which is stable to the iron catalyzed conditions.

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Synthesis and Tautomerism of Novel Quinoxalines (Part I) (새로운 Quinoxaline류의 합성과 토토머화 현상 (제1보))

  • Ho Sik Kim;Jin Hee Kim
    • Journal of the Korean Chemical Society
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    • v.47 no.3
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    • pp.241-249
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    • 2003

  • The reaction of 3-(1-ethoxycarbonyl)ethyl-1,2-dihydro-2-oxoquinoxaline (8) with hydrazine hydrate gave 3-(1-hydrazinocarbonyl)ethyl-2-hydroxyquinoxaline (9). The reaction of compound 9 with substituted benzaldehydes and heteroaryl aldehydes afforded 2-hydroxyquinoxalines (10-12), respectively. The reaction of compound 9 with alkyl (ethoxymethylene)cyanoacetates and ethoxymethylenemalononitrile resulted in the intramolecular cyclization to give the 5-amino-1-[2-(3-hydroxyquinoxalin-2-yl)propanoyl]-pyrazoles (13), respectively. Compounds 10-13 showed the tautomerism between the lactam and lactim forms in dimethyl sulfoxide solution. The tautomer ratios were determined by the $^1H$ NMR. The herbicidal and fungicidal activities of the synthesized compounds were investigated.

  • https://doi.org/10.5012/jkcs.2003.47.3.241 인용 PDF KSCI

A Model Study toward the Synthesis of Xestoquinone (Xestoquinone의 합성에 대한 모델연구)

  • Ahn Chan Mug;Ho Bum Woo
    • Journal of the Korean Chemical Society
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    • v.47 no.4
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    • pp.354-362
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    • 2003

  • A strategy for synthesis of the furan-fused tetracyclic system of xestoquinone was explored through a model study. Using 3-butyn-1-ol as a starting material, 5-iodo-1-methoxymethoxy pentyne (5) was prepared in 5 steps. Reaction of ethyl 2-phenylpropanoate with 5 gave ethyl 7-methoxymethoxy-2-methyl-2-phenyl-5-heptynoate (6) in 88% yield, and then methyl 9-oxo-4-methyl-4-phenyl-2,7-nonadiynoate (13), the key intermediate, was synthesized in 6 steps from the ester 6. Intramolecular cycloaddition reaction of 13 afforded isobenzofuran 14 in 5% yield, which was converted to the tetracyclic structure 15 in the presence of Lewis acid.

  • https://doi.org/10.5012/jkcs.2003.47.4.354 인용 PDF KSCI

Synthesis of 2-(Pyrazol-1-yl)quinoxalines and 2,3-Di(pyrazol-1-yl)quinoxalines (2-(Pyrazol-1-yl)quinoxaline류 및 2,3-Di(pyrazol-1-yl)quinoxaline류의 합성)

  • Kim, Ho-Sik;Jeong, Won-Young;Choi, Kyung-Ok;Lee, Seong-Uk;Kwag, Sam-Tag;Lee, Man-Kil
    • Journal of the Korean Chemical Society
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    • v.46 no.1
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    • pp.37-45
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    • 2002

  • The reaction of 3,6-dichloro-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(8) or 6-chloro-3-hydrazino-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(9) with substituted anilines, sulfa drugs and heteroacyl chlorides gave 2-(pyrazol-1-yl)quinoxalines(10-12). The reaction of compound 9 with alkyl (ethoxymeth-ylene) cyanoacetates resulted in the intramolecular cyclization to give 2,3-di(pyrazol-1-yl)quinoxalines(13).

  • https://doi.org/10.5012/jkcs.2002.46.1.037 인용 PDF KSCI