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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5:21 minutes

Problem 45c

Textbook Question

Show how Claisen condensations could be used to make the following compounds.
(c)

Verified step by step guidance

Step 1: Identify the target compound as a β-keto ester, which is a common product of Claisen condensation. The structure contains two carbonyl groups: one ketone and one ester, separated by a single carbon atom.

Step 2: Recall the general mechanism of Claisen condensation. It involves the reaction of two ester molecules (or an ester and a ketone) in the presence of a strong base, typically an alkoxide, to form a β-keto ester.

Step 3: Determine the starting materials. For this compound, the starting materials could be ethyl acetate (an ester) and cyclohexanone (a ketone). Cyclohexanone provides the cyclic ketone structure, while ethyl acetate contributes the ester group.

Step 4: Outline the reaction conditions. The reaction requires a strong base, such as sodium ethoxide (NaOEt), in an ethanol solvent. The base deprotonates the α-hydrogen of cyclohexanone, forming an enolate ion, which then attacks the carbonyl carbon of ethyl acetate.

Step 5: Describe the final steps of the reaction. After the nucleophilic attack, the intermediate undergoes elimination of the ethoxide group, forming the β-keto ester product. Acidic workup is typically performed to neutralize the reaction mixture and isolate 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, leading to the formation of 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, followed by the elimination of an alcohol. Understanding this mechanism is crucial for synthesizing complex organic molecules.

Enolate Ion

An enolate ion is a resonance-stabilized anion formed from a carbonyl compound, typically an aldehyde or ketone, when it is deprotonated at the alpha carbon. This ion acts as a nucleophile in various reactions, including Claisen condensation. The ability to generate and utilize enolate ions is fundamental in organic synthesis, allowing for the formation of carbon-carbon bonds.

Carbonyl Compounds

Carbonyl compounds, characterized by the presence of a carbonyl group (C=O), include aldehydes, ketones, and carboxylic acids. They are pivotal in organic chemistry due to their reactivity and ability to undergo various transformations, such as nucleophilic addition and condensation reactions. Recognizing the structure and reactivity of carbonyl compounds is essential for understanding the Claisen condensation and its applications in synthesizing complex molecules.

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Show how Claisen condensations could be used to make the following compounds.(c)

Key Concepts

Claisen Condensation

Enolate Ion

Carbonyl Compounds

Watch next

Show how Claisen condensations could be used to make the following compounds.
(c)