Question

A compound $'A'$ having the molecular formula $C+{5}H_{12}O$, on oxidation gives a compound $'B'$ with molecular formula $C_{5}H_{10}O$. Compound $'B'$ gave a $2,4-$dinitrophenylhydrazine derivative but did not answer haloform test or silver mirror test. The structure of compound $'A'$ is

• A.
• B.
• C.
• D.

Answer 1

Answer: (C)

Answer 2

Since $(B)$ on reaction with $2,4-DNP$ forms a derivative, it implies that $(B)$ has group $(B)$ gives $-ve$ Tollens? test, hence it is not an aldehyde, but it is a ketone. $(B)$ gives $-ve$ haloform test, thus it is not a methyl ketone. $(B)$ is formed from the oxidation of $(A)$, thus $(A)$ is a $2^\circ$ alcohol, and among the given options, $(A)$ is : and $\therefore(B)$ is