Cascade Multiple Diels–Alder Reactions of Styrene Derivatives with Maleimide or Maleic Anhydride

We developed novel one-pot multiple Diels–Alder reactions, which are frequently used in the construction of six-membered rings in functional molecular synthesis. We report triple and double Diels–Alder reactions with styrene derivatives, where the secondary Diels–Alder reaction takes place at a different position from that of the conventional Wagner-Jauregg reaction.