An efficient method for the acceleration of the intramolecular Diels-Alder reaction was established utilizing the internal interaction—the internal hydrogen bonding and the internal coordination of a magnesium salt. The intramolecular Diels-Alder reaction between nitrofuran derivatives and various acrylic acid derivatives give good yields of the cycloadducts when internal hydrogen bonding is present. When cyclic α, β-unsaturated ...