• 제목/요약/키워드: Epoxide opening

검색결과 52건 처리시간 0.024초

Selective Ring-opening Fluorination of Epoxide: An Efficient Synthesis of 2'-C-Fluoro-2'-C-methyl Carbocyclic Nucleosides

  • Liu, Lian-Jin;Kim, Si-Wouk;Lee, Won-Jae;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • 제30권12호
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    • pp.2989-2992
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    • 2009

  • An efficient synthetic route of novel 2′(${\alpha}$)-C-fluoro-2′(${\beta}$)-C-methyl carbocyclic nucleoside analogues is described. The key fluorinated intermediate 7 was prepared from the epoxide intermediate 5 via selective ring-opening of epoxide. Coupling of 7 with nucleosidic bases under the Mitsunobu reactions followed by deprotection afforded the target carbocyclic nucleoside analogues. The synthesized compounds were evaluated as inhibitors of the hepatitis C virus (HCV) in Huh-7 cell line in vitro.

  • https://doi.org/10.5012/bkcs.2009.30.12.2989 인용 PDF KSCI

Stereoselective Transformation of Phytosphingosine to Safingol

  • Kim, Na-Ri;Lee, Sun-Hee;Namgoong, Sung-Keon
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.695-699
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    • 2009

  • A short and efficient synthesis of (2S,3S)-safingol from commercially available D-ribo-(2S,3S,4R)-phytosphingosine is described. The highlights of the synthesis are a stereoselective one-pot transformation of a diol into an epoxide under phase transfer catalytic conditions and a regioselective epoxide-opening reduction with a hydride reagent.

  • https://doi.org/10.5012/bkcs.2009.30.3.695 인용 PDF KSCI

Study on the Optimization of Cationic Ring Opening Polymerization of Silicone-Based Epoxy Monomers for Holographic Photopolymers

  • Kim, Dae-Heum;Chung, Dae-Won
    • Macromolecular Research
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    • 제17권9호
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    • pp.651-657
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    • 2009

  • This study examined the optimum compositions of binder, photo-acid generator (PAG) and sensitizer for the cationic ring opening polymerization of 1,3-bis[2-(3-{7-oxabicyclo-[4.1.0]heptyl})]-tetramethyldisiloxane in the presence of polydimethylsiloxane with four epoxide moieties as a co-monomer. When diffractive efficiency (DE) values were compared quantitatively to analyze the effect of the binder on holographic photopolymerization, DE was affected by the viscosity of the binders and miscibility with the monomer mixture. Extremely low DE values were observed when the immiscible dimethyl silicone was used as a binder. Therefore, methylphenyl silicone, which is miscible with the monomer mixture, was used as the binder for further studies. The optimal conditions were a binder viscosity between 250 to 390 cP, and contents of the binder, PAG, and sensitizer were 75-125 wt%, > 6 wt% and 0.05 wt% to the total monomer mixture, respectively.

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전이금속염 함유 키랄 살렌 촉매에 의한 광학선택적 에폭사이드의 합성 (Enantioselective Epoxide Synthesis on the Chiral Salen Catalyst having a Transitional Metal Salt)

  • 곽소봉;키테라 라올;김건중
    • Korean Chemical Engineering Research
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    • 제46권4호
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    • pp.769-776
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    • 2008

  • 키랄성 말단기의 에폭사이드는 키랄중간체나 여러 출발물질로서 다양하게 이용되기 때문에 그 선택적인 합성법은 매우 유용하다. 본 연구에서는 염화코발트(II), 염화철(III) 및 질산아연(II)을 각각 함유한 키랄 코발트 살렌 촉매를 새로이 합성하고 그 특성을 평가하였다. 질량분석과 EXAF분석을 통하여 형성된 촉매 착체의 구조를 평가하였다. 합성한 촉매는 방향족 에폭사이드인 스타이렌 옥사이드와 페닐글리시딜 에테르의 속도차에 의한 비대칭 가수분해적 고리열림반응과 글리시틸부틸레이트의 합성반응에 적용하여 그 활성과 선택성을 조사하였다. 합성이 용이한 전이금속염함유 살렌착체 촉매는 물을 친핵체로 하는 라세믹 에폭사이드의 고리 열림을 통하여 99%ee 이상을 나타낼 정도의 매우 높은 광학선택성을 보였으며, 적은 양의 첨가로도 높은 활성을 보였다. 본 연구에서 적용한 촉매씨스템은 키랄 에폭사이드 및 1,2-디올 중간체의 제조에 매우 효과적이었다.

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