acids are good catalysts for Diels−Alder reactions between furan and acrylonitrile and methyl acrylate at room temperature. When 2,5-dimethylfuran is used as the diene, yields of the Diels−Alderadducts with methyl acrylate are lower, due in part to the appearance of aromatization products. The use of microwave activation results in some cases in good yields of aromatic products and, as such, constitutes