Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

25. Condensation Chemistry

Claisen Condensation

Organic Chemistry

25. Condensation Chemistry

Claisen Condensation

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4:55 minutes

Problem 36c

Textbook Question

Predict the products of self-condensation of the following esters.
(c)

Verified step by step guidance

Step 1: Recognize that the reaction involves the self-condensation of esters under basic conditions. The base used here is sodium methoxide (NaOCH₃), which will deprotonate the alpha-hydrogen of the ester to form an enolate ion.

Step 2: Identify the alpha-hydrogen in the ester structure. The alpha-hydrogen is located on the carbon adjacent to the carbonyl group (C=O). This hydrogen is acidic and can be removed by the base to form the enolate ion.

Step 3: The enolate ion acts as a nucleophile and attacks the carbonyl carbon of another ester molecule. This nucleophilic attack leads to the formation of a new carbon-carbon bond.

Step 4: After the nucleophilic attack, the intermediate undergoes proton transfer and elimination of the methoxide ion (CH₃O⁻), resulting in the formation of a β-keto ester. This is the typical product of ester self-condensation.

Step 5: Write the final product structure, which is a β-keto ester. The β-keto ester will have a ketone group (C=O) and an ester group (COOCH₃) separated by one carbon atom. Ensure the cyclic structure of the original ester is preserved in the product.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Claisen Condensation

Claisen condensation is a reaction between two esters or an ester and a carbonyl compound in the presence of a strong base, typically an alkoxide. This reaction results in the formation of a β-keto ester or a β-diketone. The mechanism involves the deprotonation of an ester to form an enolate ion, which then attacks the carbonyl carbon of another ester, leading to the formation of a new carbon-carbon bond.

Enolate Ion

An enolate ion is a resonance-stabilized anion formed by the deprotonation of a carbonyl compound, such as an ester or ketone. This ion is crucial in nucleophilic addition reactions, as it acts as a nucleophile that can attack electrophiles, such as carbonyl carbons. The stability of the enolate ion is influenced by the substituents on the carbonyl compound, which can affect the reaction's regioselectivity and reactivity.

Self-Condensation of Esters

Self-condensation of esters refers to the reaction where a single type of ester undergoes Claisen condensation with itself, leading to the formation of a β-keto ester or a β-diketone. This process requires a strong base to generate the enolate ion from the ester, which then attacks another molecule of the same ester. The reaction typically results in the formation of a new carbon-carbon bond and the release of an alcohol as a byproduct.

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Predict the products of self-condensation of the following esters.(c)

Key Concepts

Claisen Condensation

Enolate Ion

Self-Condensation of Esters

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Predict the products of self-condensation of the following esters.
(c)