Metal‐Free One‐Pot Synthesis of Benzofurans

Ethyl acetohydroxamate was efficiently arylated with diaryliodonium salts at room temperature under transition‐metal‐free conditions. The obtained O ‐arylated products were reacted in situ with ketones under acidic conditions to yield substituted benzo[ b ]furans through oxime formation, [3,3]‐rearrangement, and cyclization in a fast and operationally simple one‐pot fashion without using excess reagents. Alternatively, the O ‐arylated products could be isolated or transformed in situ to aryloxyamines or O ‐arylaldoximes. The methodology was applied to the synthesis of Stemofuran A and the formal syntheses of Coumestan, Eupomatenoid 6, and (+)‐machaeriol B.