Write the structural formula of the compounds having the following IUPAC names:
Butane-2, 3-dione

Explanation

The reactions indicate that both the compounds (A) and (B) are the halogen derivatives of butane and may be expressed as `C_4 H_9 X,` where X = Cl, Br or I.
` underset((A) or (B ) )(C_4 H_9 X) + 2H overset(Zn Cu )to underset("Butane ")(C_4 H_(10)) +HX`
The compound (A) yields n-octane on treatment with sodium and ether (Wurtz reaction).
` RX + 2Na +RX overset("Ether ")to R-R +2NaX`
Since R-R is `CH_3CH_2CH_2CH_2CH_2CH_2CH_2CH_3` in the present case, R should be `CH_3 CH_2CH_2CH_2 `- . Hence, compound (A) should be n-butyl halide and should have the structure `CH_3 CH_2 CH_2 CH_2 X`. Its reaction can be written as
`underset("n-butyl halide (A)")(CH_3 CH_2 CH_2 CH_2 X) + 2Na + underset((A ))(CH_3 CH_2CH_2 CH_2 CH_2 X) overset ("ether ")to CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CH_2 CH_3 + 2NaX`