The presence of radicals in some familiar looking addition reactions can completely change the product.
Remember our friendly addition reaction halogenation? Notice that you achieve a vicinal dihalide in this reaction.
Now we see this reaction. Note that the only difference is the presence of a radical initiator.
This one added condition will lead to the formation of a mixture of allylic alkyl halides. Here’s the full mechanism:
Concept: The products of Allylic Chlorination.1m
Concept: Mechanism of Allylic Bromination.1m
Example: Predict the product(s) of the following reaction.5m