Photolysis of Saturated Four‐Membered Rings with Two Exocyclic Double Bonds: A Photoextrusion Route to (Hetero)Methylenecyclopropanes

Abstract

The photochemistry of cyclobutanes and saturated four‐membered heterocycles with two exocyclic double bonds (except bisalkylidenecyclobutanes) is reviewed. Emphasis is laid on photoproducts rather than on mechanism, with special regard for the formation of (hetero)methylenecyclopropanes via photoextrusion of small stable molecules.