question_answer

An organic compound [A] with molecular formula \[{{C}_{9}}{{H}_{10}}O\] forms an orange-red precipitate with 2, 4-DNP reagent and gives yellow precipitate on heating with iodine and \[NaOH.\] It does not reduces Tollen's reagent or Fehling's solution nor it decolourises bromine water as Baeyer's reagent. On drastic oxidation with chromic acid, it gives a carboxylic acid having molecular formula \[{{C}_{7}}{{H}_{6}}{{O}_{2}}.\] Identify the compound [A].

A)          

B)

C)                 

D)

Correct Answer: A

Solution :

[a]

The organic compound with molecular formula \[{{C}_{9}}{{H}_{10}}O\] forms an orange-red ppt. with 2, 4-DNP reagent and gives yellow ppt. on heating with \[{{I}_{2}}\] and NaOH. This confirms the presence of carboxyl group in compound . Also, it does not reduces Tollen's reagent or Fehling's solution, this shows it is a kenotic group and not an aldehyde. As it does not decolourises bromine water it indicates the absence of unsaturated bonds. The reactions are as follows: