20.14 : 급진적 자동산화

Oxidation of organic compounds in the presence of air or atmospheric oxygen is termed autoxidation.

It is a free radical chain reaction consisting of initiation, propagation, and termination steps.

In the initiation step, an initiator abstracts hydrogen from the organic compound to form a carbon-centered radical.

The radical then enters the first propagation step, where it couples with the molecular oxygen to form a peroxy radical.

In the second propagation step, the peroxy radical abstracts hydrogen from another organic compound molecule forming the product peroxide and regenerating the carbon-centered radical.

The regenerated radical further propagates the chain reaction.

Finally, in the termination step, two carbon-centered radicals couple together to form a non-radical product.

Generally, the autoxidation process is initiated by light. In the absence of light, the process is very slow. For this reason, most organic chemicals are stored in dark bottles.

In particular, compounds with allylic and benzylic hydrogens are more susceptible to autoxidation as the free radicals formed in the initiation step are resonance stabilized.