• Synthetic experiments in the benzopyrone series - Part XI. Conversion of carthamidin and isocarthamidin into herbacetin and tangeretin

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    • Keywords


      Concentrate Sulphuric Acid; Anhydrous Potassium Carbonate; Aqueous Alkali; Alkaline Hydrogen Peroxide; Synthetic Experiment

    • Abstract


      A convenient method of providing confirmation of the constitution of carthamidin and isocarthamidin is to convert them into herbacetin and tangeretin. The earlier claim of Bargellini to have prepared herbacetin tetramethyl ether by the oxidation of 2-hydroxy-3:4:6:4′-tetramethoxy chalkone with alkaline hydrogen peroxide could not be supported. This reaction yields the corresponding benzalcoumaranone and not flavonol in agreement with the behaviour of analogous and simpler chalkones having a methoxyl group in the 6-position. An example is described where even a methyl group in that position brings about the same result. However by the action of amyl nitrite and hydrochloric acid carthamidin and isocarthamidin tetramethyl ethers yield the corresponding flavonol derivatives.

    • Author Affiliations


      N Narasimhachari1 T R Seshadri1

      1. Departments of Chemistry, Andhra and Delhi Universities, India
    • Dates


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