In this reaction, phenol (C6H5OH) reacts with hydrochloric acid (HCl) in the presence of heat to form chlorobenzene.
The hydroxyl group on the phenol is replaced by a chlorine atom through electrophilic aromatic substitution.
The structure of the product is:
A compound (A) with molecular formula $C_4H_9I$ which is a primary alkyl halide, reacts with alcoholic KOH to give compound (B). Compound (B) reacts with HI to give (C) which is an isomer of (A). When (A) reacts with Na metal in the presence of dry ether, it gives a compound (D), C8H18, which is different from the compound formed when n-butyl iodide reacts with sodium. Write the structures of A, (B), (C) and (D) when (A) reacts with alcoholic KOH.