A ketone A which undergoes haloform reaction gives compound B on reduction. B on heating with sulphuric acid gives compound C, which forms mono-ozonide D. The compound D on hydrolysis in presence of zinc dust gives only acetaldehyde. Write the structures and IUPAC names of A, B and C. Write down the reactions involved.

Explanation

Compound D on hydrolysis in the presence of zinc dust gives acetaldehyde. Therefore, the compound C must be
`underset(C" (But-2-ene)")(CH_(3)-CH=CH-CH_(3))`
The compound C is obtained from B, therefore, B should be
`underset("B(Butan-2-ol)")(CH_(3)-underset(OH)underset(|)(CH)-CH_(2)-CH_(3))`
B is obtained by the reduction of A, therefore A should be
`underset("A(Butan-2-one)")(CH_(3)-underset(O)underset(||)C-CH_(2)-CH_(3))`
Compounds containing `CH_(3)CO` - group give haloform reaction. The reactions can be explained as under :