The preparation of phenol from cumene involves the following reaction:
\[
\text{Cumene} \xrightarrow{\text{O}_2, \text{H}_2\text{SO}_4} \text{Phenol + Acetone}
\]
Cumene is first oxidized to cumene hydroperoxide, which then undergoes acid-catalyzed cleavage to form phenol and acetone.