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Q. Question Major product is :-

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Solution:

In this elimination reaction, hoffman product is major product.
This reaction take place by (Unimolecular elimination via conjugate base) mechanism, in which first step is involves fast reversible removal of proton from beta carbon by base with formation of carbanion. Second step is slow and rate determining step in which carbanion (conjugate base) ejects the leaving group to give alkene.
This reaction depends on the stability of carbanion and poor leaving group ability of leaving group.
Strong electron withdrawing group (here is present) must be present in the alkyl halide to form stable carbanion and poor leaving group like stabilises the conjugate base.
In given reactant,carbanion formed at is more stable than carbanion at , so in first step proton will be remove from , hence least substituted alkene will be major product.