What do you get when you do a free radical bromination with butene?

Question

Will you get the brominated alkene or a substituted alkane by getting rid of the double bond

Is your reactant 2Br?

Answer 1

The reagent is the bromine atom, produced when the bromine molecule is homolyzed by light. Free-radical halogenation does not attack carbon-carbon double bonds. Instead, it is selective for the allylic position - that is, the position next to the double bond. Did you mean but-1-ene or but-2-ene?

For but-1-ene, the bromine attacks carbon 3 to give 3-bromobut-1-ene. Whereas for but-2-ene the bromine atom attacks carbon 1 or 4, but these are equivalent anyways, and your product is 1-bromobut-2-ene. Multiple bromination may occur in either case.