Example 6.5 · Part 3

case of alkyl halides, alkyl halides undergo S N reaction very fast because of the high stability of carbocations. We can sum up the order of reactivity of alkyl halides towards S N and S N reactions as follows: For the same reasons, allylic and benzylic halides show high reactivity towards the S N reaction. The carbocation thus formed gets stabilised through resonance (Unit , Class XI) as shown below: In the following pairs of halogen compounds, which would undergo S N reaction faster?