Question

A compound A(C2H6O) on oxidation by PCC gave B, which on treatment with aqueous alkali and subsequent
heating furnished C. B on oxidation by KMnO,, forms a monobasic carboxylic acid with molar mass 60 g mol^-1.
Deduce the structures of A, B and C.​

Answer 1

A is Ethanol, B is Ethanal or Acetaldehyde, C is 2- Butenal.

1) PCC( Pyridinium Chloro Chromate ) is a mild oxidising agent, which oxidizes primary alcohol to aldehydes and secondary alcohols to ketones.

2) Ethanol's( CH3 CH2 OH) reaction with PCC gives Acetaldehyde (CH3 CHO).

3) Treatment of Acetaldehyde with aqueous alkali gives 3 hydroxy butanal which on heating reduce to 2- butenal ( CH3 CH CH CHO).

4) Oxidation of Acetaldehyde (CH3 CHO) gives Ethanoic Acid ( CH3 COOH) which has a molar mass of 60 grams/ mol.