An organic compound A with molecular formula `C_(9)H_(10)O` gives positive DNP and iodoform tests. It does not reduce. Tollen's reagent or Fehling reagent and does not decolourless bromine water or Bayer's reagent. On drastic oxidation with chronic acid, compound A gives a carboxylic acid having molecular formula `C_(7)H_(6)O_(2)`. Deduce the structur eof organic compound A and write all the chemical reactions involved.

Explanation

(1) Positive DNP test and +ve iodoform test suggests that it is a carbonyl compound containing `CH_(3)-overset(O)overset(||)C-` group but `-ve` Tollen's and Fehling's tests suggest that it must be a methyl ketone and not an aldehyde.
(2) Molecular formula of compound A shows high degree of unsaturation but as it does not decolourless to `Br_(2)` water and Bayer's reagent, it must not be an aliphatic alkene, rather it must include an aromatic ring also.
(3) Thus compound A can be
Let us try all the reactions involved in the question.