Question

Identify the name reaction

• A. Stephen reaction
• B. Etard reaction
• C. Gatterman-koch reaction
• D. Rosenmund reduction

Answer 1

The Correct Option is C

The reaction depicted in the image is called the Gatterman-Koch reaction. This reaction involves the formylation of aromatic compounds like benzene to form benzaldehyde.

1. The reaction uses carbon monoxide (CO) and hydrogen chloride (HCl) in the presence of a Lewis acid catalyst such as anhydrous aluminum chloride (AlCl₃) or cuprous chloride (CuCl).
2. The main purpose of this reaction is to introduce an aldehyde group (–CHO) onto the aromatic ring.

Explanation:

The setup typically involves bubbling CO and HCl through a solution of an aromatic ring and the catalyst. When benzene is used, the Gatterman-Koch reaction results in the formation of benzaldehyde:

Reaction: C₆H₆ + CO + HCl → C₆H₅CHO

This method is particularly useful because it directly converts benzene into benzaldehyde in one step.

This is distinct from other reactions listed in the options:

• Stephen reaction: Used to convert nitriles to aldehydes.
• Etard reaction: Involves the oxidation of aromatic methyl groups to aldehydes using chromyl chloride.
• Rosenmund reduction: Reduces acyl chlorides to aldehydes using hydrogen and a palladium catalyst.

Thus, the correct answer is Gatterman-Koch reaction.