Ketone `(A)`, which indergoes halform reaction, give compound `(B)` on reduction. `(B)` on heating with `H_(2)SO_(4)` gives compound `(C )`, which forms mono-ozonide `(D). (D)` on hydrolysis in the presence of `Zn` dust gives only acetaldehyde. Identify `(A). (B)`, and `(C )`. Write down the reactions involved.

Explanation

Ketone `(A)` gives haloform reaction, so it must contain `(Me-CO-)` group. Ketone on reduction gives `2^(@)` alcohol. (B), which gives alkene `(C )` with `H_(2)SO_(4)`. Alkene on ozonolysis followed by reduction with `Zn` dust gives `MeCHO`. So, the structure of alkene `(C )` is:

So `(A)` is: Butan-`2`-one, `(B)` is: Butan-`2`-ol, `(C )` is: Butan-`2`-one.