Synthesis of 5,8‐dimethoxy‐2(1<i>H</i>)‐quinolinones by intramolecular Wittig reaction

Abstract

Abstract The title compounds 12 , which are key intermediates for antitumoral diazaquinomycin A analogues, are obtained by intramolecular Wittig reaction of 1‐[3′,6′‐dimethoxy‐2′‐(α‐oxoacylamino)phenyl]alkyltriphenylphosphonium salts 11 , which are prepared via lithiation of 2′,5′‐dimethoxy‐ N ‐pivaloylaniline 6. The applicability of this route to polysubstituted 2(1 H )‐quinolinones 12 and 17 is examined.