All aldehdes can made to undergo the Cannizzaro reaction by treatment with aluminium ethoxide. Under these conditions, the acid and alcohol are combined to form an ester. The reaction is called

Options

A. Claisen reaction
B. Perkin reaction
C. Aldol condensation
D. Tischenko reaction

Answer

To solve the question regarding the reaction that occurs when aldehydes are treated with aluminum ethoxide, we will follow these steps:

### Step 1: Understand the Cannizzaro Reaction
The Cannizzaro reaction is a redox reaction that occurs in aldehydes that do not have alpha-hydrogens. In this reaction, one molecule of the aldehyde is oxidized to a carboxylic acid, while another molecule is reduced to an alcohol.

### Step 2: Identify the Role of Aluminum Ethoxide
Aluminum ethoxide (Al(OEt)3) can facilitate the Cannizzaro reaction by acting as a Lewis acid. It coordinates with the carbonyl oxygen of the aldehyde, making it more electrophilic and susceptible to nucleophilic attack.

### Step 3: Formation of Ester
Under the conditions provided (using aluminum ethoxide), the aldehyde reacts with itself to form an ester instead of undergoing the typical Cannizzaro reaction. This is because the aluminum ethoxide promotes the reaction of the aldehyde with the alcohol formed during the reaction.

### Step 4: Name the Reaction
The reaction that occurs under these conditions, where the acid and alcohol combine to form an ester, is known as the **Tishchenko reaction**.

### Final Answer
The reaction is called the **Tishchenko reaction**.

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