The Room‐Temperature Stabilization of Bicyclo[2.2.2]oct‐1‐ene and Bicyclo[3.2.1]oct‐1‐ene

Retardation through incarceration: The highly strained anti-Bredt bridgehead olefin bicyclo[2.2.2]oct-1-ene (1) is remarkably stable at 60 °C, if generated photochemically inside the hemicarcerand 2 (see picture). The surrounding host not only prevents the dimerization of 1, but also retards strongly its intramolecular retro-Diels–Alder reaction by several orders of magnitude.