Test: Reaction Mechanism of Haloalkanes & Haloarenes - NEET MCQ

The correct answer is option A
Both the ethers obtained by the two routes have opposite but equal optical rotation
One of the ether is obtained as a racemic mixture
Step II & III both are S2N  reaction and both have inversion Step II has inversion but step III has retention

By the question (B) is correct answer.

S_N2’ mechanism

Example of pinacol-pinacolone rearrangement

Given compound is in configuration due to walden inversion on attack by  we get 'R' configuration

Example of pinacol pinacolone rearrangement.

Stericaily hindered base leads to elimination product.

The correct answer is Option A
Least hindered halides give the fastest SN₂ reaction as the hindrance increases. As the hindrance increases, the occurrence of SN₂ reaction decreases.

The SN2 (Substitution Nucleophilic Bimolecular) mechanism is characterized by:

1. Single-step process: The nucleophile attacks the substrate and the leaving group departs simultaneously (concerted mechanism).
2. Backside attack: The nucleophile approaches the carbon atom opposite to the leaving group, leading to inversion of configuration (Walden inversion).
3. Rate of reaction: Depends on the concentration of both the substrate (haloalkane) and nucleophile, hence bimolecular.