• Bulletin of the Korean Chemical Society
• /
• 제32권1호
• /
• pp.153-156
• /
• 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.