Question

Aldehydes are prepared by reducing nitriles to corresponding imines with stannous chloride in the presence of hydrochloric acid. This reaction is called:

Options

• Gatterman-Koch reaction

• Friedel-Crafts reaction

• Etard reaction

• Stephens reaction

Answer 1

Stephens reaction

Explanation:

Reaction for preparation of aldehydes by reducing RCN in presence of SnCl₂ is Stephen's Reaction.

The mechanism of the reaction is as shown below.

\[\ce{SnCl2 + 2HCl -> SnCl2 + 2[H]}\]

\[\begin{array}{cc}
\phantom{...................................................}\ce{O}\\
\phantom{...................................................}||\\
\ce{R - C ≡ N + 2[H] + HCl -> R - CH = NH.HCl ->[Boiling H2O] R - C - H + NH4Cl}\\
\end{array}\]