question_answer

Allylic bromination is carried out by

A)  n-bromosuccinimide

B)  \[B{{r}_{2}}/C{{S}_{2}}\]

C)  \[HBr/{{H}_{2}}{{O}_{2}}\]

D)  \[HOBr\]

Correct Answer: A

Solution :

                 Key Idea Alkene containing allylic H-atoms can undergo substitution at high temperature. \[C{{H}_{3}}CH=C{{H}_{2}}+C{{l}_{2}}\xrightarrow{{{500}^{o}}C}\underset{\begin{smallmatrix}  | \\  Cl \end{smallmatrix}}{\mathop{C}}\,{{H}_{2}}-CH=C{{H}_{2}}\]                                                       allyl chloride NBS (N-bromosuccinimide) is a reagent used for the specific purpose of brominating alkenes at the allylic position.