Write the isomers of the compound having formula C4H9Br.
There are four isomers of the compound having the formula C4H9Br. These isomers are given below.
(a)
1−Bromobutane
(b)
2−Bromobutane
(c) 
1−Bromo−2−methylpropane
(d) 
2−Bromo−2−methylpropane
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.