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 of aldehydes with aluminum ethoxide, we will break down the process step by step.

### Step-by-Step Solution:

1. **Understanding the Cannizzaro Reaction**:
- The Cannizzaro reaction typically occurs with 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.

**Hint**: Recall that the Cannizzaro reaction is specific to aldehydes without alpha hydrogens.

2. **Role of Aluminum Ethoxide**:
- When aldehydes are treated with aluminum ethoxide (Al(OEt)3), the conditions allow for all aldehydes to undergo a reaction that leads to the formation of an ester.

**Hint**: Aluminum ethoxide acts as a catalyst that modifies the reaction pathway.

3. **Mechanism of the Reaction**:
- The reaction begins with the nucleophilic attack of the oxygen atom from the aluminum ethoxide on the carbonyl carbon of the aldehyde. This forms a tetrahedral intermediate.
- The tetrahedral intermediate rearranges, leading to the formation of an ester.

**Hint**: Focus on the nucleophilic attack and the rearrangement that leads to ester formation.

4. **Formation of the Ester**:
- The final product of this reaction is an ester, which is formed by the combination of the aldehyde and the ethoxy group from aluminum ethoxide.

**Hint**: Remember that the reaction results in the formation of an ester from the aldehyde and the ethoxy group.

5. **Naming the Reaction**:
- The specific reaction that occurs when aldehydes are treated with aluminum ethoxide to form an ester is known as the Tishchenko reaction.

**Hint**: The Tishchenko reaction is characterized by the formation of an ester from aldehydes under specific catalytic conditions.

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