Synthesis of furanonaphthazarin derivatives

Abstract

A three-step synthesis of the 58-dihydroxy-2-(1-methylethyl)naphtho[2,3-b]furan-4,9-dione (9) starting from 2-hydroxy-5,8-dimethoxy-1,4-naphthoquinone (4), is described. Further treatment of (9) with selenium dioxide in the presence of pyridine N-oxide as co-oxidant gave 2-(1-hydroxy-1-methylethyl)naphtho[2,3-b]furan-4,9-dione (10).