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JEE Main levelSingle correct optionDifficulty 2 of 3o4116

2,2-Dimethylpropan-1-ol (neopentyl alcohol) is heated with conc. $H X_{2} SO X_{4}$ . The major alkene formed is

A2-methylbut-2-ene
B2-methylbut-1-ene
C3-methylbut-1-ene
Dpent-1-ene

Answer: A

The alcohol has no beta-hydrogen, so direct elimination is impossible. Ionisation (with concerted methyl migration) gives the tertiary cation

(CH X_{3}) X_{2} C X^{+} CH X_{2} CH X_{3}

. Loss of H from the

CH X_{2}

group gives the trisubstituted alkene 2-methylbut-2-ene.

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