Consider the reaction of ${\text{CH}}_3{\text{C(OH)(CH}}_3{\text{)CH}}_2{\text{CH}}_3$ with concentrated ${\text{H}}_2{\text{SO}}_4$ at $443\text{ K}$. What is the major product formed?

Solution

1. Protonation of the hydroxyl group leads to the formation of a tertiary carbocation ${\text{CH}}_3{\text{C}}^{\text{+}}({\text{CH}}_3){\text{CH}}_2{\text{CH}}_3$.
2. Elimination of a proton from the adjacent carbon atoms can occur to form either 2-methyl-1-butene or 2-methyl-2-butene.
3. According to Zaitsev's rule, the more substituted alkene, 2-methyl-2-butene, is the thermodynamically stable major product.
4. Hence the answer is (B).