Question

An organic compound A, on treatment with ethyl alcohol gives a carboxylic acid B and compound C. Hydrolysis of C under acidic conditions gives B and D. Oxidation of D with KMnO₄ also gives B, B on heating with Ca(OH), gives E (molecular formula. C₃H₆O). E does not give Tollen's test and does not reduce Fehling's solution but forms a 2,4-dinitrophenyl hydrazone. Identify A, B, C, D and E.

Answer 1

Hence, compound D is primary alcohol and compounds D and B have same number of carbon atoms. Compounds -B (carboxylic acid) and D (p-alcohol) are obtained with hydrolysis of compound C So. compound C is an ester

Compound B and C are obtained by the reaction of compound A with C₂H₅OH So. compound ,A is acid anhydride and compound C is ethyl ester when compound C is ethyl ester therefore, compound D is ethyl alcohol and compound B is CH₃COOH due to reaction (ii) and (iii). Thus, compound A is (CH₃CO)₂ O so It gives following reaction (as above).

Compound B on heating with Ca(OH)₂ gives compound E (C₃H₆O) which does not give Tollen's test and does not reduce Fehling's solution hut. form 2. 4-dinitrophenvl hydrazone. Hence. compound E is ketone (ie CH₃COCH₃)