• 제목/요약/키워드: Wittig Reaction

검색결과 55건 처리시간 0.022초

1-히드록시카르바페넴의 합성에 관한 연구 (Studies on the Synthesis of 1-Hydroxycarbapenems)

  • 유종현;박정호;구양모;이윤영
    • 대한화학회지
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    • 제42권1호
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    • pp.69-77
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    • 1998
  • 4-styryl-2-azetidinone 7b의 bromoacetate에 의한 N-알킬화, 가오존분해, 산화, 말론산 에틸 마그네슘과의 축합 및 디아조 전달반응의 일련의 과정을 거처서 (3S,4S)-1-(t-butoxycarbonylmethyl)-3-[(S)-1-(t-butyldimethylsilyloxy)ethyl]-4-(2-diazo-2-ethoxycarbonyl-1-oxoethyl)-2-azetidinone(14)을 합성하였다. 또한 4-formyl-2-azetidinone 5b 의 Wittig 반응, ethoxycarbonylformonitrile oxide와의 1,3 이중극성 고리화 첨가반응, 촉매 수소화 및 디아조화 반응의 일련의 과정을 거쳐서 (3S,4S)-3-[(S)-1-(t-butyldimethylsilyloxy)ethyl]-4-(3-diazo-3-ethoxycarbonyl-1-hydroxypropyl)-2-azetidinone(21)을 합성하였다. 그러나 화합물 14 또는 21을 $Rh_2(OAc)_4$ 로 처리하여 1-hydroxycarbapenem 또는 1-hydroxycarbapenam으로 고리화하는 것을 성공하지 못하였다.

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One-pot, Three-component Synthesis of Fully Substituted 1,3,4-Oxadiazole Derivatives from (N-Isocyanoimino)triphenylphosphorane, Aromatic Carboxylic acids and (1R)-(-)-Campherchinon

  • Ramazani, Ali;Nasrabadi, Fatemeh Zeinali;Abdian, Behnaz;Rouhani, Morteza
    • Bulletin of the Korean Chemical Society
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    • 제33권2호
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    • pp.453-458
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    • 2012
  • Reactions of (N-isocyanimino)triphenylphosphorane with (1R)-(-)-campherchinon in the presence of aromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.

크로토니테논에 대한 합성방법 (A Synthetic Approach towards Crotonitenone)

  • 김영균
    • Journal of the Korean Wood Science and Technology
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    • 제23권4호
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    • pp.98-107
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    • 1995
  • 천연물 중 casbene-type diterpenoid의 하나인 crotonitenone의 합성이 시도되었다. 합성 방법으로는 crotonitenone의 각 부분을 먼저 합성하여 이들을 합하는 방법(convergent method)을 적용하였으며, 각 부분이 최종물질에 적합한 sterochemistry를 갖게 하기 위하여 시작물질로는 chiron으로 S-(-)-citronellol과 IS-chrysanthemic acid를 사용하였다. 환구조를 형성하는데 중요한 역할을 할 TBDMS protecting group이 붙은 phosphonium salt(synthon A) 가 고압반응으로부터 고수율 (70%)로 생성되었다. 또한, 중요한 반응으로서 synthon A와 hydroxy lactone(synthon B)과의 Witting reaction이 성공적으로 이루어졌다. 그러나, TBDMS protecting group의 존재하에 이중 치환된 이중결합(disubstituted double bond)과 삼중치환된 것과의 선택적인 환원의 어려움으로 인하여 최종 물질의 합성방법이 재고되었으며 이에 대해 간단히 논하였다.

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Chemiluminescence Properties of Polymeric Fluorophores Containing Distyrylarylene Unit

  • 이희우;김철희;공명선
    • Bulletin of the Korean Chemical Society
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    • 제22권7호
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    • pp.727-731
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    • 2001
  • Conjugated-non-conjugated alternating block copolymers containing distyrylarylene units were synthesized via Wittig reaction for chemiluminescent fluorophores. The polymers were differentiated from others by the presence of aromatic unit in the chromophoric block. When UV-VIS, photoluminescence and chemiluminescence spectra of these materials were compared with copolymers, a strong bathochromic effect was observed. A more pronounced red shift and higher chemiluminscence efficiency were observed in the polymer with anthracene ring. Sodium salicylate-catalyzed reaction of bis(2-carbopentyloxy-3,5,6-trichlorophenyl) oxalate with hydrogen peroxide produced a strong chemiluminescence from blue to yellow-green light emission with wavelength of 450-537 nm in the presence of the fluorophore. The chemiluminescent intensity decayed exponentially. The glow of chemiluminescence maintained more than l2 hr and was visible with the naked eye.

Stilbene 발광 유도체를 가지는 Polyurethane을 기본으로 하는 고분자의 합성 및 특성 (Syntheses and Characterization of Polyurethane Polymers with Versatile Stilbene Chromophores)

  • 진영읍;노지영;박성수;주창식;서홍석
    • 공업화학
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    • 제22권4호
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    • pp.348-352
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    • 2011
  • 본 연구에서는 펜던트 타입의 고분자인 폴리우레탄에 스틸벤 유도체를 가진 다양한 발색단을 곁가지로 도입하고, 이를 연결하는 방식으로 분자를 디자인하고 합성하였다. 모노머 분자인 N,N-bis(2-hydroxyethyl)amino-4'-cyanostilbene, N,N-bis(2-hydroxyethyl) amino-4'-methoxy stilbene, N,N-bis(2-hydroxyethyl)amino-4'-acetylstilbene, N,N-bis (2-hydroxyethyl) amino stilbene은 Wittig 반응을 이용하여 합성하였고, N,N-bis(2-hydroxyethyl)amino-4'-nitrostilbene는 Knoevenagel 축합반응을 이용하여 합성하였다. 합성된 물질의 흡수 및 형광 스펙트럼의 측정으로부터, 치환기로 전자 끌게 작용기를 도입한 경우 그 정도에 따라 스펙트럼이 장파장으로 이동하며, 반대로 전자 주게 작용기가 도입된 경우는 단파장 이동하는 것을 확인 하였다. 반면, $NO_2$가 치환된 경우 그 자체가 빛을 소멸시키는 쾐쳐로 작용하여 PL이 관측되지 않았다.

Synthesis of Novel 2'(β)-Methyl-5'-deoxyapiose Nucleoside Phosphonic Acid Analogues as Antiviral Agents

  • Hong, Joon Hee
    • 통합자연과학논문집
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    • 제8권1호
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    • pp.48-55
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    • 2015
  • Novel 2'(${\beta}$)-methyl-5'-deoxyapiose purine phosphonic acid analogues were designed and synthesized from 2-propanone-1,3-diacetate. Condensation successfully proceeded from a glycosyl donor 9 under Vorbr${\ddot{u}}$ggen conditions. Condensation of aldehyde 14 with Wittig reagent [(diethoxyphosphinyl)methylidene] triphenylphosphorane gave the desired nucleoside phosphonate analogues 15. Ammonolysis and hydrolysis of phosphonates gave the nucleoside phosphonic acid analogue 17 and 19. The synthesized nucleoside analogues were subjected to antiviral screening against HIV-1. The adenine analogue 19 exhibited weak in vitro activities against HIV-1.

Systematic Approaches for Blue Light-emitting Polymers by Introducing Various Naphthalene Linkages into Carbazole Containing PPV Derivatives

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • 제14권5호
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    • pp.258-262
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    • 2013
  • Poly(2,3-naphthalenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene), 2,3-PNCPV, poly(2,6-naphthalene vinylenealt- N-ethylhexyl-3,6-carbazolevinylene), 2,6-PNCPV, and poly(1,4-naphthalenevinylene-alt-N-ethylhexyl-3,6- carbazolevinylene), 1,4-PNCPV were synthesized through the Wittig polycondensation reaction. The conjugation lengths of the polymers were controlled by differently linked naphthalenes in the polymer main chain. The resulting polymers were completely soluble in common organic solvents, and exhibited good thermal stability at up to $400^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 357-374 nm and 487-538 nm, respectively. The carbazole and 2,3-linked naphthalene containing 2,3-PNCPV showed a blue PL peak at 487 nm. A single-layer light-emitting diode was fabricated with an ITO/polymer/Al configuration. The electroluminescence (EL) emission of 2,3-PNCPV was shown at 483 nm.

Carpenter bee pheromone의 2-methyl-5(S)-hexanolide의 부분 입체선택적 합성 (The diastereoselective synthesis of 2-methyl-5(S)-hexanolide)

  • 장재혁;이상준;김정한
    • Applied Biological Chemistry
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    • 제37권1호
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    • pp.25-29
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    • 1994
  • Ethyl acetoacetate를 빵효모가 환원해 생산한 ethyl-(S)-3-hydroxy-butyrate(2a)를 키 랄 출발물질로 하여 수목에 피해를 끼치는 해충인 carpenter bee의 수컷이 분비하는 성 페로몬인 cis-2-methyl-5-hexanolide(1)을 diastereomer로 합성하였다. 역합성적 분석을 통한 합성계획으로부터 T-Goal로 Wittig반응을 잡고 출발물질을 환원하여 얻은 알데히드 4와 triethyl 2-phosphonopropionate(7)을 Horner-Emmons반응시켜 ${\alpha},{\beta}$-불포화 에스테르 5를 얻은 뒤 catalytic hydrogenation과 lactonization을 시켜 carpenter bee 페로몬 1을 전체수율 37%로 쉽고 간단하게 합성하였다.

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${\beta}-Lactamase$ 억제작용이 기대되는 7-Arylidene Cephalosporanate 유도체의 합성 (Synthesis of 7-Arylidene Cephalosporanates for ${\beta}-lactamase$ Inhibitor)

  • 이종민;임철부;임채욱
    • 약학회지
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    • 제52권4호
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    • pp.311-315
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    • 2008
  • The synthesis of 7-arylidene cephalosporanates for ${\beta}-lactamase$ inhibitor was described. The reactions of substituted benzyl halides $[1]{\sim}[3]$ with triphenylphosphine gave triphenylphcsphonium chlorides $[4]{\sim}[6]$. These phosphonium salts were treated with n-butyllithium to give ylides, which were reated with 7-oxocephalosporanate [7] by Wittig reaction to afford the 7-exomethylene cephalosporanates $[8]{\sim}[10]$. These cephalosporanates were oxidized to cephalosporanate sulfones $[11]{\sim}[13]$ with mCPBA. The deprotection of benzhydryl cephalosporanate $[8]{\sim}[13]$ with $AlCl_3$ and $NaHCO_{3}$ gave sodium salts of 7-arylidene cephalosporanates $[14]{\sim}[19]$.

Reactions of Some Furan-3-ones with 2,3-Diaminopyridine and its Derivatives

  • Sacmacl, Mustafa;Bolukbasl, Hilal;Sahin, Ertan
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.90-94
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    • 2012
  • The furan-2-ylidene acetates (3a-d), obtained from the furan-2,3-diones (1a-b) and methyl/ethyl (triphenylphosphoranylidene)-acetates (2a-b), were converted via the Michael type reactions with 2,3-diaminopyridine and its derivatives (4a-c) into the corresponding pyrrol-2-ylidene-acetates (5a-j) in moderate yields (45-94%). Structures of these compounds were determined by the IR, NMR, elemental analysis, and X-ray diffraction method.