• Nuclear oxidation in the flavones and related compounds - Part XIV. Constitution of quercetagitrin

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      https://www.ias.ac.in/article/fulltext/seca/028/02/0031-0039

    • Keywords

       

      Baicalein; Baicalin; Aqueous Sodium Hydroxide; Anhydrous Potassium Carbonate; Scutellarin

    • Abstract

       

      Synthetic confirmation for the constitution of quercetagitrin is provided. The pentamethyl-quercetagetin obtained by the complete methylation and hydrolysis of the glucoside is finally ethylated and the product shown to be identical with a synthetic sample of 7-ethoxy-3∶5∶6∶3′∶4′-pentamethoxy flavone (V) made from 2-hydroxy-4-ethoxy-ω: 6-dimethoxy-acetophenone (VI) using oxidation with persulphate, Allan-Robinson condensation and final methylation as stages. The ketone (VI) is conveniently made by the alkali fission ofO-7-ethyl-3∶5∶3′∶4′-tetramethyl-quercetin obtained from quercimeritrin. This mixed ether of quercetin is also made independently by synthesis and this constitutes a synthetic confirmation of the constitution of quercimeritrin. Further, the transformations show the relationship between quercimeritrin and quercetagitrin as 7-glucosides. The most convenient synthetic route for the ketone (VI) is through the galangin derivative (XVI).

    • Author Affiliations

       

      S Rajagopalan1 T R Seshadri1

      1. Department of Chemistry, Andhra University, Waltair
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