Organic Chemistry – Some Basic Principles and Techniques

The most stable carbocation from the following is :

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Answer

(3) [figure]

Solution

A benzylic cation is stabilised by the ring; a +M group at para adds one more resonance form:

[figure] [figure]

–OMe at meta cannot conjugate (only –I); CH3 gives only +I.

∴ (C) > (B) > (D) > (A)

Answer: (3)