In the cumene to phenol preparation in presence of air, the intermediate is

The industrial preparation of phenol from cumene occurs in two steps.

Cumene (isopropylbenzene) undergoes aerial oxidation, in which oxygen attacks the benzylic carbon to form a hydroperoxide intermediate:

$$\mathrm{C_6H_5CH(CH_3)_2 \xrightarrow[\text{air}]{O_2} C_6H_5C(CH_3)_2OOH}$$

The intermediate formed is cumene hydroperoxide.

On treatment with dilute acid, cumene hydroperoxide undergoes cleavage to give phenol and acetone:

$$\mathrm{C_6H_5C(CH_3)_2OOH \xrightarrow{H^+} C_6H_5OH + (CH_3)_2CO}$$

Among the given structures:

• Option A represents phenyl acetate.

• Option B represents isopropyl phenyl ether.

• Option C represents cumene (starting material).

• Option D represents cumene hydroperoxide, containing the characteristic $$-OOH$$ group.

Hence, the intermediate formed during the oxidation of cumene is

$$\boxed{\text{Cumene hydroperoxide}}$$

Therefore, the correct answer is $$\boxed{\text{Option D}}$$.