Question

For the given reaction the possibility of a substitution versus no reaction must be considered. If a substitution is predicted will it take place by a $S_{N}1$ or a $S_{N}2$ mechanism? If chiral centres are present will the configuration change.

Answer 1

This reaction undergoes by $S_{N}2$ mechanism as $CN$ is strong nucleophilic and strong nucleophiles favour $S{N}^2$ mechanism and the attack of nucleophilic occurs from a backside.

Configuration won't change.