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JEE Main levelSingle correct optionDifficulty 2 of 3o4192

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

A2-methylbut-1-ene
B3-methylbut-1-ene
C2-methylbut-2-ene
Dno alkene, since the alcohol has no beta-hydrogen

Answer: C

The alcohol has no beta-hydrogen, but ionisation is accompanied by a 1,2-methyl shift to give the tertiary cation

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

. Proton loss gives mainly the more stable alkene, 2-methylbut-2-ene.

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