• Title/Summary/Keyword: Pyranonaphthoquinones

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Concise Synthesis of (±)-Rhinacanthin A, Dehydro α-Lapachone, and β-Lapachone, and Pyranonaphthoquinone Derivatives

  • Wang, Xue;Chen, Ye;Lee, Yong-Rok
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.153-156
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    • 2011
  • A concise synthesis of (${\pm}$)-rhinacanthin A is achieved in two steps by epoxidation of dehydro-$\alpha$-lapachone, followed by chemo- and regioselective reduction. Dehydro-$\alpha$-lapachone was also synthesized in two steps starting from 4-methoxy-1-naphthol by ethylenediamine diaetate (EDDA)-catalyzed benzopyran formation and a CAN-mediated oxidation reaction. $\beta$-Lapachone was synthesized in three steps from 4-methoxy-1-naphthol by benzopyran formation, catalytic hydrogenation, and Jones oxidation. As additional reactions, synthesis of pyranonaphthoquinone derivatives with the pyranokunthone B skeleton has been achieved in a single step from readily available 2-hydroxy-6-methoxy-1,4-naphthoquinone and 2-hydroxy-7-methoxy-1,4-naphthoquinone.