An organic compound A ($\text{C}_4\text{H}_9\text{Cl}$) in reaction with $\text{Na}$/diethyl ether gives a hydrocarbon which on monochlorination gives only one chloro derivative. A is:

The reaction of an alkyl halide with sodium metal in dry ether to form a higher alkane is known as the Wurtz reaction . When tert-butyl chloride ($\text{C}_4\text{H}_9\text{Cl}$) reacts with $\text{Na}$ in diethyl ether, it theoretically yields 2,2,3,3-tetramethylbutane: $2(\text{CH}_3)_3\text{C-Cl} + 2\text{Na} \xrightarrow{\text{dry ether}} (\text{CH}_3)_3\text{C-C}(\text{CH}_3)_3 + 2\text{NaCl}$ The resulting hydrocarbon, 2,2,3,3-tetramethylbutane, is highly symmetrical. All 18 of its hydrogen atoms are equivalent (all are primary hydrogens belonging to the six methyl groups attached to equivalent quaternary carbons). Because all the hydrogen atoms are identical, its free radical monochlorination will result in the replacement of any one of these hydrogens, yielding only a single monochloro derivative (1-chloro-2,2,3,3-tetramethylbutane). The other butyl chlorides yield hydrocarbons with multiple non-equivalent hydrogen atoms, which would produce a mixture of several monochloro derivatives.