Diels–Alder reaction
Because the Diels–Alder reaction exchanges two π bonds for two σ bonds, it is intrinsically thermodynamically favored in the forward direction. However, a variety of strategies for overcoming this inherent thermodynamic bias are known. Complexation of Lewis acids to basic functionality in the starting material may induce the retro-Diels–Alder reaction, even in cases when the forward reaction is intramolecular.