3,3-Dimethylbut-1-ene reacts with HCl and the major product is formed through a 1,2-methyl shift. Count the number of CH3 groups (carbons bonded to three hydrogens) in one molecule of this major product.

JEE Main levelNumerical answerDifficulty 2 of 3o2195

3,3-Dimethylbut-1-ene reacts with $HCl$ and the major product is formed through a 1,2-methyl shift. Count the number of $CH X_{3}$ groups (carbons bonded to three hydrogens) in one molecule of this major product.

Numerical answer type, tolerance 0.5.

The major product is

(CH X_{3}) X_{2} CCl - CH (CH X_{3}) X_{2}

, 2-chloro-2,3-dimethylbutane. It has two

CH X_{3}

on C2 and two on C3, so the count is 4. The starting alkene had only 3, since the shift moved one

CH X_{3}

from a quaternary carbon.