(•) Predict the product of the Claisen reactions shown. (c)

Verified step by step guidance

1. Identify the starting materials involved in the Claisen reaction. Typically, this involves two esters or an ester and a ketone.
2. Determine the presence of an alpha-hydrogen in one of the esters, which is necessary for the formation of the enolate ion.
3. Use a strong base, such as an alkoxide ion, to deprotonate the alpha-hydrogen, forming the enolate ion.
4. The enolate ion will then attack the carbonyl carbon of the other ester, leading to the formation of a new carbon-carbon bond.
5. After the nucleophilic attack, a tetrahedral intermediate is formed, which will collapse to expel the leaving group (usually an alkoxide ion), resulting in a β-keto ester or a β-diketone as the product.

Key Concepts

Claisen Condensation

The Claisen condensation is a fundamental reaction in organic chemistry where two esters or an ester and a carbonyl compound react in the presence of a strong base to form a β-keto ester or a β-diketone. This reaction involves the nucleophilic attack of an enolate ion on the carbonyl carbon of another ester, leading to the formation of a new carbon-carbon bond.

Enolate Ion Formation

Enolate ions are key intermediates in the Claisen condensation, formed when a strong base abstracts a proton from the α-carbon of an ester. This results in a resonance-stabilized anion that can act as a nucleophile, attacking the carbonyl carbon of another ester or carbonyl compound, which is crucial for the reaction to proceed.

Product Prediction

Predicting the product of a Claisen reaction involves understanding the structure of the starting materials and the mechanism of the reaction. The final product will typically be a β-keto ester or a β-diketone, depending on the reactants used. Analyzing the sterics and electronics of the reactants can also help in determining the major product formed.