Question

What is the major product of the following reaction?

 

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

To solve this problem, we need to determine the major product of the reaction shown. The reaction involves an aldehyde, specifically an aldol reaction, in a basic medium. Aldol reactions typically occur between aldehydes or ketones with at least one alpha hydrogen.

Steps involved in the aldol reaction:

1. The base (\(OH^-\)) deprotonates the alpha hydrogen of the aldehyde, creating an enolate ion.
2. The enolate ion then attacks the carbonyl carbon of another aldehyde molecule.
3. This results in the formation of a β-hydroxy aldehyde (aldol product).
4. Upon heating or further reaction, dehydration may occur, leading to an α,β-unsaturated aldehyde.

In the given reaction, the following steps take place:

1. The base (\(OH^-\)) removes an alpha hydrogen from the aldehyde, forming an enolate ion.
2. The enolate ion then nucleophilically attacks the carbonyl carbon of another aldehyde molecule.
3. This forms a β-hydroxy aldehyde as an intermediate.
4. Finally, the β-hydroxy aldehyde undergoes dehydration (loss of water) to form an α,β-unsaturated aldehyde as the final product.

The correct product, as provided in the options, is:

Conclusion: The major product of the reaction is an α,β-unsaturated aldehyde formed after dehydration of the β-hydroxy aldehyde intermediate.