• Title/Summary/Keyword: Aldol

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Synthesis, Characterization and Correlation Analysis in Styryl 6-Methoxy-2-Naphthyl Ketones (Styryl-6-Methoxy-2-Naphthyl Ketone 유도체의 합성 및 특성 분석)

  • Thirunarayanan, G.
    • Journal of the Korean Chemical Society
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    • v.51 no.2
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    • pp.115-124
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    • 2007
  • A series of α, β-unsaturated ketones are synthesized by Crossed - Aldol condensation reaction, from ecofriendly 6-methoxy-2-naphthyl ketones and substituted benzaldehydes under solvent free conditions using silica-sulfuric acid as a catalytic reagent. The yields of ketones are more than 90% and the catalyst was reusable for further run. There is no appreciable decrease in the yield of product and the activity of catalyst. These chalcones were characterized by their physical constants and spectral data (IR, 1H-, 13C-NMR and Mass). These spectral data are subjected to correlate various Hammett substituent constants with single and multiparameter correlation equations. From the results of statistical analysis the influence of electronic effects of substituents on the spectral data of the ketones were explained.

Stereoselective Routes to Erythronolide A Seco Acid (Erythronolide A 개발(開發)의 광학선택적(光學選擇的)인 합성방법(合成方法))

  • Kim, Young-Gyu
    • Applied Chemistry for Engineering
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    • v.2 no.1
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    • pp.12-29
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    • 1991
  • Stereoselective synthetic efforts for erythronolide A seco acid are reviewed from the first discovery of erythromycin A in 1952 up to the end of 1990. The synthetic strategies for construction of ten asymmetric centers embedded in an aglycone of erythramycin A have mostly been realized by the stereoselective preparation of the key fragments followed by coupling them. The synthetic methods employed for the key fragments can be classified into three categorie; a carbohydrate approach, a cyclic approach and an acyclic approach. The coupling has largely been reduced to practice by either aldol-type additions or Wittig olefinations of the key fragments.

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Efficient Synthesis of Biologically Interesting Natural Pyranochalcones from Mallotus Philippensis and Their Unnatural Derivatives

  • Xia, Likai;Lee, Yong-Rok
    • Bulletin of the Korean Chemical Society
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    • v.32 no.spc8
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    • pp.2921-2927
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    • 2011
  • This paper describes efficient synthetic approaches for isolating biologically interesting natural pyranochalcones and their unnatural derivatives from Mallotus Philippensis. The key strategies involve ethylenediamine diacetate-catalyzed benzopyran formation reactions and base-catalyzed aldol reactions.

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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    • v.29 no.6
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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.