Question

How is an aldehyde obtained from alkyl nitrile? 

OR 

What is Stephen reaction? 

OR

Write a note on Stephen reaction.

Answer 1

(1) An ethereal solution of a nitrile is reduced to imine hydrochloride by SnCl₂ in the presence of HCl gas. 

Further, 

Imine hydrochloride on acid hydrolysis gives aldehyde. 

This reaction is called Stephen reaction.

(2) Alternatively, nitriles are selectively reduced by diisobi.ityl aluminium hydride (DIBAI-H) lo imines which on acid hydrolysis to aldehydes.