A ketone [A] which undergoes haloform reactions gives compound [B] on reduction. [B] on heating with sulphuric acid gives compound [C] which forms monozonide [D}. On hydrolysis in the presence on zinc dust gives acetaldehyde. Identify [A], [B] , [C] and [D]. Write the 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.