Question

In the correct order, what are the three general steps in the mechanism of a claisen reaction? multiple choice

O enolate formation
O elimination
O nucleophilic addition

Answer 1

The correct answer is order 1,3 and 2. The correct order for the Claisen reaction mechanism is enolate formation, nucleophilic addition, and elimination, leading to the synthesis of α,β-unsaturated aldehyde or ketone.

Step-by-step explanation:

The Claisen reaction mechanism involves three general steps ordered as follows:

1. Enolate formation: First, an enolate ion is generated from a ketone or an aldehyde by deprotonation with a base. This enolate is a strong nucleophile ready for the subsequent step.
2. Nucleophilic addition: The formed enolate acts as a nucleophile and adds to another aldehyde or ketone acting as an electrophile. This addition forms a new carbon-carbon bond and results in an alkoxide anion.
3. Elimination: Lastly, the alkoxide anion undergoes protonation to form a hydroxyaldehyde or a hydroxyketone (aldol), which then eliminates a water molecule to yield an α,β-unsaturated aldehyde or ketone.

Understanding this sequence is crucial to grasping the Claisen reaction, which is fundamental in both the synthesis and chemistry of carbonyl compounds.