The major product of the following reaction is : CH3CH2CH = O → alkali excess HCHO reflux ?

Question

The major product of the following reaction is : 

\(CH_3CH_2CH = O \underset{\text{reflux}}{\xrightarrow{\overset{\text{excess HCHO}}{\text{alkali}}}} ?\) 

(1) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{OH}\)

(2)
\(CH_3 - \underset{CH_2 - OH}{\underset{|}{C}H} - CH = 0\)

(3) 

(4) 
\(CH_3 - \underset{CH_2}{\underset{||}{C}} - CH = 0\)

Answer 1

Correct option is : (3) 

This is an example of Tollen‟s reaction i.e. multiple cross aldol followed by cross Cannizaro reaction

\(CH_3CH_2CH = O \underset{Alkali}{\xrightarrow{2HCHO}} CH_3- \underset{\underset{CH_2-OH}|}{\overset{\overset{CH_2 - OH}|}C}-CHO\)