An organic compound [A] with molecular formula `C_(9)H_(10)O` forms an arage-red precipitate [B] with `2,4` DNP reagent. Compound [A] gives yellow precipiatate [C] on heating wihth iodine in the presence of soedium hydroxide along with a colourless compound [D]. The compound [A] does not reduce Tollen's reagent or Fehling's solution nor does it decolourise bromine water or Baeyer's reagent. On drastic oxidation with chromic acid, compound [A] gives a crboxylic acid [E] having molecular formula `C_(7)H_(6)O_(2)`. Deduce the strcutres of the organic compounds [A] to [E].

Explanation

(i) Positive test with 2,4 DNP and negtive tests with Tollen's reagent and Fehling solution suggest that the compound [A] is a ketone. Since it responds to iodoform test `(I_(2)//NaOH)`, it must be a methyl ketone `(CH_(3)COR)`.
(ii) The molecular formula suggests a high degree pf unsaturation which is ruled out because it does not decolourise either bromine water or Baeyer's reagent. Thus, we many conclude that it is an aromatic compound and the side chain has `-COCH_(3)` group .
Thus, the compound [A] is `C_(6)H_(5)CH_(2)COCH_(3)` (I-Phenylpropanone).
The reaction involved are as follows: