The reaction involves a bromination in the presence of heat, which typically leads to the formation of a benzylic bromination product. In this case, the hydrogen at the benzylic position (the carbon adjacent to the benzene ring) will be replaced by a bromine atom, forming 1-bromo-2-phenylethane as the major product.
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.