Question

An organic compound with the molecular formula $C_8H_8O$ forms $2,4-DNP$ derivative, reduces Tollen’s reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives $1,2$-benzene dicarboxylic acid. The organic compound is

• A. 2-ethylbenzaldehyde
• B. 2-methylbenzaldehyde
• C. acetophenone
• D. 3-methylbenzaldehyde
• E. phenylacetaldehyde

Answer 1

Answer: (B)

Since, the compound forms $2,4 -DNP$ derivative, so it must be a carbonyl compound.

It reduces tollen's Reagent and undergoes Cannizzaro reaction, so it must contain a $- CHO$ group and no $\alpha$ - $H$ atoms.

Thus, its possible formula may be $CH _{3} C _{6} H _{4} CHO$. Since, it gives $1, 2$-benzene-dicarboxylic acid when subjected to oxidatin, so $- CH _{3}$ and $- CHO$ groups must be present at successive positions. Thus, the structure of the compound must be



The reactions occurring are as follows