Question

$\left(A\right),\left(B\right)$ and $\left(C\right)$ are three non-cyclic functional isomers of a carbonyl compound with molecular formula $C_4{H}_{8}O$. Isomers $\left(A\right)$ and $\left(C\right)$ give positive Tollen's test whereas isomer $\left(B\right)$ does not give Tollen's test but gives positive Iodoform test. Isomers $\left(A\right)$ and $\left(B\right)$ on reduction with $Zn\left(Hg\right)/conc$. $HCl$ give the same product $\left(D\right)$.

Write the structures of $\left(A\right),\left(B\right),\left(C\right)$ and $\left(D\right)$.

Answer 1

(B) does not give Tollens' test but gives positive Iodoform test. Hence, (B) is a methyl ketone. (A) and (C) give positive Tollens' test . Hence, they are aldehydes. Isomers (A) and (B) on rediction with Zn(Hg)/conc. HCl give the same product (D). It is an example of Clemmeson reduction in which carbonyl group is reduced to methylene group.