Question

The organic chloro compound, which shows complete stereochemical inversion during a $S_{N}2$ reaction is:

• A. $(C{H}_3{)}_{2}CHCl$
• B. $C{H}_{3}Cl$
• C. $(C{}_2{H}_5{)}_{2}CHCl$
• D. $(CH3{)}_{3}CCl$

Answer 1

The correct option is B $C{H}_{3}Cl$

Primary haildes like $C{H}_{3}Cl$ prefer $S_{N}2$ reaction by a backside nucleophilic attack.

In a backside attack, the nucleophile attacks the electrophilic center on the side that is opposite to the leaving group results in inversion of configuration. The secondary and tertiary alkyl halides prefer front side attack due to steric hindrance. That results in the retention of configuration.