Question

Among the following, the most reactive towards alcoholic $KOH$ is :

• A. $CH_2 = CHBr$
• B. $CH_3COCH_2CH_2Br$
• C. $CH_3CH_2Br$
• D. $CH_3CH_2CH_2Br$

Answer 1

Answer: (D)

$CH_3CH_2CH_2Br$

Answer 2

Propyl bromide $\left( CH _{3} CH _{2} CH _{2} Br \right)$ is most reactive towards alcoholic KOII, in the presence of which it gives propene by elimination reaction. The reason is that in it $C - Br$ bond has maximum polarity. In vinyl bromide, $(-Br$ bond has partial double bond character due to delocalization lone pair of electron on $Br$ atom.