20.7 : Образование радикалов: удаление

Radical formation via the elimination process is the mechanistic reverse of the radical addition reaction. It occurs due to an unstable radical.

For instance, dibenzoyl peroxide undergoes homolysis to form a radical, which is unstable. So, it undergoes elimination to generate a phenyl radical and carbon dioxide.

The site of the unpaired electron in the radical is the α position. During the elimination reaction, the unstable radical cleaves the carbon–carbon σ bond at the β position to yield a stable radical.

Accordingly, there forms a double bond between the α and β positions, resulting in two product fragments—a radical species and an unsaturated molecule.