An organic compound `(A)` on treatment with ethyl alcohol gives a carboxylic acid `(B)` and compound `( C)`. The hydrolysis of `( C)` under acidic conditions gives `(B)` and `(D)`. Oxidation of `(D)` with `KMnO_4` also gives `(B)`. `(B)` on heating with `Ca(OH)_2` gives `(E)` (molecular formula, `C_3 H_6 O`). `(E)` does not give Tollens test and does not reduce Fehling's solution but forms a `2,4-`dinitrophenyl hydrazone. Identify `(A),(B), ( C), (D)`, and `(E)`.

Explanation

M.F. of `E = C_3 H_6O`. It does not reduce Fehling solution and does not give Tollens. test but forms 2,4-dinitrophenylhydrazone,
`:.` E is a ketone, i.e., `CH_3COCH_3` (propanone)
Propanone is obtained by heating the carboxylic acid B with `Ca(OH)_2`,
`:.` B should be acetic acid.
`underset((B))(2CH_3COOH ) + Ca(OH)_2 to underset("Calcium acetate")(Ca(CH_3COO)_2) overset("Heat")to CaCO_3 + underset((E))(CH_3COCH_3)`
Since oxidation of (D) with `KMnO_4` gives acetic acid.
`:.` D should be ethanol.
`underset("Ethanol(D)")(CH_3CH_2OH) underset(-H_2O)overset((O))to CH_3 CHO overset((O))to underset((B))(CH_3COOH)`
Since hydrolysis of C gives ethanoic acid (acetic acid) and ethanol,
`:.` C is ethyl ethanoate `(CH_3COOC_2H_5)`
`underset((C))(CH_3COOC_2H_5) overset(H^(+))hArr underset((B))(CH_3COOH ) + underset((D))(C_2H_5OH)`
(A) on treatment with ethanol, gives `CH_3COOH` and `CH_3COOC_2H_5`.
`:.(A)` is acetic anhydride.
`underset((A))((CH_3CO)_2O ) + CH_3CH_2OH to CH_3COOH + CH_3 COOC_2H_5`