An organic compound (A) of molecular formula CH6 reacts with Br2 in the presence of FeCI3 gives (B) of formula C6HBr. B on treatment with mg in the presence of dry ether gives (C) compound (C) on treatment with dry ice followed by hydrolysis gives a compound (D) of molecular formula C7H6O2 . Identify A,B,C,D and explain the reactions involved.
