Anodic Addition Reactions of 1, 5-Dimethoxy- and 1,4,5-Trimethoxynaphthalenes. A Convenient Synthesis of Methoxyjuglone

Abstract

While anodic oxidation of substituted benzenes and anthracenes has been extensively studied, there are few studies of naphthalene derivatives.¹ Our need for a convenient economical route to methoxyjuglone² prompted an investigation of the anodic oxidation of 1, 5-dimethoxynaphthalene, 1. ^3,4 We report that preparative anodic oxidation of 1 affords an isolable 1, 4-dihydronaphthalene, 2, which is converted to 1, 4, 5-trimethoxynaphthalene, 3, by acid. Subsequent anodic oxidation of 3 followed by acid hydrolysis affords methoxyjuglone, a versatile intermediate in anthracycline synthesis.