Question

A mixture of two alcohols $3-$methyl$-1-$butanol and $2-$methyl$-1-$butanol, given chiefly $2-$methyl$-2-$butene when dehydrated with acid. $2-$methyl$-2-$butene is converted into $2-$methyl$-2-$butanol with approximately 90% yield by treatment with 50% aqueous solution of sulphuric acid at $0^{\circ }$ C. Write equation showing mechanism of conversions.

Answer 1

In presence of an acid, alcohol undergoes dehydration to form an alkene. Rearrangement results in formation of more substituted alkene which is more stable.
The mechanism is as given below.