One-pot synthesis of 4H-chromene and dihydropyrano[3, 2-c]chromene derivatives in hydroalcoholic media

Abstract

4ff-Chromenes and dihydropyrano[3, 2-c]chromenes are obtained in good to excellent yields by a simple, mild and efficient procedure using poly(N, N'-dibromo-N-ethyl-benzene-1, 3-disulfonamide) [PBBS] and N, N, N, N,-tetrabromobenzene-1, 3-disulfonamide [TBBDA ] as catalysts. © 2011 Sociedade Brasileira de Química.