Which one of the following compounds most readily undrgoes substitution by $\mathrm{S}_{\mathrm{N}} 2$ mechanism?

Question

Aicharya · Accepted Answer

The increasing order of the nucleophilic substitution by $\mathrm{S}_{\mathrm{N}} 2$ mechanism is tert
$-$ alkyl halide $ < $ sec alkyl halide $ < $ primary alkyl halide.
Compound B is primary alkyl halide.
Hence it most readily undergoes substitution by $\mathrm{S}_{\mathrm{N}} 2$ mechanism.
Note: compound $\mathrm{A}$ is also primary alkyl halide but in it, the carbon attached to is more hindered. ,

Which one of the following compounds most readily undrgoes substitution by $\mathrm{S}_{\mathrm{N}} 2$…

Solution