The carbon atoms at which bromination will take place are:

Options

A. 1,2 and 3
B. 4 and 5
C. 1, 3,4 and 5
D. 1, 3 and 4

Answer

D

Explanation

N-Bromosuccinimide (NBS) is frequently used to brominate allyhc positions because it allows a radical substitution reaction to be carried out without subjecting the reactant to a relatively high concentration of `Br_2` that could add to its double bond. Carbon atoms at positions 1,3 and 4 are allylic carbons. The carbon atom at position 5 is not allylic since it becomes acidic due. to presence of carbonyl carbon at the alphaposition: