NEETChemistryHaloalkanes and Haloarenes
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Neopentyl chloride is highly reactive towards S _ N 2 reaction because it is a primary alkyl halide. Reason (R): The bulky tert-butyl group attached to the -carbon in neopentyl chloride causes severe steric hindrance in the transition state. In the light of the above statements, choose the most app
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A).
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A).
- C(A) is true but (R) is false.
- D(A) is false but (R) is true.
Correct answer
D. (A) is false but (R) is true.
Step-by-step solution
Assertion (A) is false because despite being a primary ( 1^ ) alkyl halide, neopentyl chloride (1-chloro-2,2-dimethylpropane) is practically unreactive towards S _ N 2 mechanisms. Reason (R) is true. In an S _ N 2 reaction, the nucleophile attacks from the backside of the leaving group. In neopentyl chloride, the -carbon is attached to a highly bulky tert-butyl group at the -position. This creates severe steric hindrance, blocking the approach of the nucleophile and making the transition state highly unstable (high