Question

A ketone A $\left(C_4{H}_{8}O\right)$, which undergoes haloform reaction gives compound B on reduction. B on heating with sulphuric acid gives a compound C which forms mono-ozonide D. D on hydrolysis in presence of zinc dust gives only acetaldehyde E. Identify A, B, C, D and E. Write the reactions involved.

Answer 1

A Ketone $A\left(C_4{H}_{8}O\right)$ undergoes haloform reaction, So the Ketone should have $-\underset{\parallel }{C}-{CH}_3$ group.

$O$

So the structure of $A$ is ${CH}_3-{CH}_2-\underset{\parallel }{C}-{CH}_3$.

$O$

Now the reactions are :

A (butane$-2-$ene) on reduction gives butan$-2-ol$

(B) Which on heating with $H_2{SO}_4$ gives a alkene named but$-2-$ene (C). $C$ forms mono-ozonide $D$ which on hydrolysis in presence $Zn$ dust to form acetaldehyde $\left(E\right)$.