• 제목/요약/키워드: Diels-Alder

검색결과 120건 처리시간 0.021초

First Concise Total Syntheses of Biologically Interesting Nicolaioidesin C, Crinatusin C1, and Crinatusin C2

  • Jung, Eun-Mi;Lee, Yong-Rok
    • Bulletin of the Korean Chemical Society
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    • 제29권6호
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    • pp.1199-1204
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    • 2008
  • The efficient and concise total syntheses of naturally occurring dihydrochalcone nicolaioidesin C, crinatusin C1, and crinatusin $C_2$ have been achieved from the readily available 2,6-dihydroxy-4-methoxyacetophenone and 2,4-dihydroxy-6-methoxyacetophenone. The key steps in the synthetic strategy were aldol reaction and Diels-Alder reaction.

Polymer-Attached Triphenylamine 양이온 라디칼의 합성 (Synthesis of Polymer-Attached Triphenylamine Cation Radical)

  • 차기혁;진명종
    • 공업화학
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    • 제5권3호
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    • pp.438-442
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    • 1994
  • 매우 유용한 양이온 라디칼인 trlphenylaminium hexachloroantimonate가 불용성 폴리머체에 정량적으로 접합되어졌다. 그 폴리머 양이온 라디칼은 딜스-알더 반응형태의 이분자화 반응에 촉매로서 효과적이었으며 여러번 재사용 되어질 수 있음을 알 수 있었다.

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의사분자 착물의 응용 (제1보). 열중합 개시기구 제안 (The Application of the Pseudo Molecular Complex to Thermal Polymerization (Ⅰ). Proposal of A New Initiation Mechanism)

  • 박병각
    • 대한화학회지
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    • 제18권6호
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    • pp.447-452
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    • 1974
  • 多數의 熱共重合 反應組들에 對하여 pseudo molecular complex 形成이 可能한가를 理論的으로 調査하였던바 例外없이 pseudo molecular complex 形成이 가능하였다. 卽, pseudo molecular complex 形成이 共重合反應組들의 共通性임을 발견하였다. 그래서 熱共重合反應은 pseudo molecular complex를 경유하여 反應이 進行하는 하나의 可能한 開始機構를 提案하였다.

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4-데옥시로도마이시논 유도체의 합성 (Synthesis of 4-Deoxyrhodomycinone Derivatives)

  • 노영쇠;김선자;조인호
    • 약학회지
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    • 제41권1호
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    • pp.7-13
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    • 1997
  • A regiospecific total synthesis on the precursor(18b) of rhodomycinones is described. The anion of 3-carbomethoxy-1(3H)-isobenzofuranone(13) was respectively condensed wi th naphthalenone (12) and butenoate(8) derivatives which were, prepared by two different synthetic routes to afford 9-ethyl-6,7-dihydroxy 7,8,9,10-tetrahydronaphthacene-5,12 dione(18b) after oxidation and reduction.

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Total Synthesis of (±)-Aspidospermidine Starting from 3-Ethyl-5-bromo-2-pyrone

  • Cho, Hyun-Kyu;Tam, Nguyen Thanh;Cho, Cheon-Gyu
    • Bulletin of the Korean Chemical Society
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    • 제31권11호
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    • pp.3382-3384
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    • 2010
  • A new synthetic route to ($\pm$)-aspidospermidine was devised, starting from the cycloadduct of 3-ethyl-5-bromo-2-pyrone with vinyl sulfide through a tandem conjugate addition-alkylation sequence. The requisite 3-ethyl-5-bromo-2-pyrone was prepared via the C3-selective Pd-catalyzed coupling reaction with $Et_3Al$-dimethylaminoethanol complex.

MO Theoretical Studies on Stereoelectronic Control in the Addition Reaction of 1, 4-Benzoquinone-4-(O-methyloxime)$^*$

  • Ik-Choon Lee;Eun-Sook Han
    • Bulletin of the Korean Chemical Society
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    • 제4권1호
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    • pp.41-44
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    • 1983
  • The chlorine addition and Diels-Alder cycloaddition of cyclopentadiene to 1, 4-benzoquinone-4-(O-methyloxime) have been studied MO theoretically. It has been shown that the reactions occur predominantly to the quinone ring double bond which is oriented anti to the nitrogen lone pair due to an n-${\sigma}^*$ interaction between the nitrogen lone pair, n, and the app. vicinal bond, causing the ${\pi}$ bond to be weakened and destabilized due to the less conjugation from reduced delocalization.

Synthesis of 6-Alkoxy-3-(1-hydroxyalkyl)-5-nitro-4,5,6,7-terahydroindole-4-carboxylates

  • 김호현;구양모;이윤영
    • Bulletin of the Korean Chemical Society
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    • 제20권8호
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    • pp.929-934
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    • 1999
  • 2-( β-Alkoxyvinyl)-4-(1-hydroxyalkyl)pyrroles (14) were synthesized from 4-acylpyrrole-2-carboxylates (8) by sequential reduction of their acyl and alkoxycarbonyl groups to give 4-(1-hydroxyalkyl)pyrrole-2-carbalde-hydes (13) followed by Wittig reaction of the aldehydes with the ylide of alkoxymethylphosphonium chloride. Diels-Alder reaction of 2-(β-alkoxyvinyl)-4-(1-hydroxyalkyl)pyrroles with trans-methyl β-nitroacrylate gave 6-alkoxy-3-(1-hydroxyalkyl)-5-nitro-4,5,6,7-tetrahydroindole-4-carboxylates (3).

열처리 조건에 따른 Pentacene 성장과 화학반응에 대한 연구

  • ;손재구;권학용;김홍배
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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    • pp.63-67
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    • 2005
  • Pentacene channel OTFT(organic thin film transistor)을 SiOC 절연박막 위에서 film by thermal evaporation 방법을 이용하여 성장시켰다. CVD 방법으로 증착시킨 SiOC 절연막은 조성비에 따라 특성이 달라지므로 절연막 위에서의 펜타센의 화학적 반응을 조사하기 위해서 inorganic-type인 $O_2/(BTMSM\;+\;O_2)$ = 0.5의 비율을 갖는 SiOC 박막을 사용하였다. 팬타센 분자의 말단에서 SiOC 표면에서 Diels-Alder 반응에 의한 이중결합이 깨어지면서 안정된 성장을 하지만 온도가 높아감에 따라 표면에서의 $SN_2$(bimolecular nucleophilic substitution) 반응과 연쇄적인 화학반응에 의해 팬타센의 성장을 방해하는 것으로 나타났다.

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