Predict the major, organic product for the following reaction sequence. <img src="https://media.pearsoncmg.com/ph/esm/ecs_mullins_organic1e/msa/content/practice-test/img/Ch20_Q10_QT.jpg" alt="The figure illustrates a series of three reactions to obtain the desired target product. The first reaction contains three reactants. The first reactant has the following structure: A 3-carbon alkane chain is depicted as a line structure using 2 zigzag lines. C 3 is double bonded to O above and single bonded to O E t on the lower right. The second reactants are N a O E t and E t O H written over the reaction arrow. The third reactant is H superscript plus quench written under the reaction arrow. The second reaction contains two reactants. The first reactants are N a O E t and E t O H written over the reaction arrow. The second reactant written under the reaction arrow has the following structure: A 2-carbon alkane chain is depicted as a line structure using 1 line. C 2 is single bonded to B r on the lower right. The third reaction contains two reactants. The first reactant is H 2 O written over the reaction arrow. The second reactant is H 2 S O 4 written under the reaction arrow. Delta is written under the reaction arrow." />

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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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Multiple Choice

Predict the major, organic product for the following reaction sequence.

The figure illustrates the structure of a molecule. A 6-carbon alkene chain is depicted as a line structure using 5 zigzag lines. A double bond is present between C 3 and C 4. C 3 is single bonded to O H above. C 4 is single bonded to C H 3 below in the form of a line.

The figure illustrates the structure of a molecule. A 5-carbon alkane chain is depicted as a line structure using 4 zigzag lines. C 3 is double bonded to O above. C 4 is single bonded on the lower left to C 2 of a 2-carbon alkane chain depicted as a line structure using 1 line. C 4 is single bonded to C H 3 on the lower right in the form of a line. C 5 is double bonded to O above and single bonded to O H on the lower right.

The figure illustrates the structure of a molecule. A 6-carbon alkane chain is depicted as a line structure using 5 zigzag lines. C 3 is double bonded to O above. C 4 is single bonded to C H 3 below in the form of a line.

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The first step involves the use of sodium ethoxide (NaOEt) in ethanol (EtOH) as a base to deprotonate the alpha hydrogen of the ethyl acetoacetate, generating an enolate ion.

The enolate ion then undergoes an intramolecular Claisen condensation, where it attacks the carbonyl carbon of another ester group, forming a beta-keto ester.

After the Claisen condensation, an acid quench (H+) is used to neutralize the reaction mixture, resulting in the formation of a beta-keto ester.

In the second reaction sequence, the beta-keto ester is treated again with NaOEt and EtOH, forming another enolate ion. This enolate ion then performs a nucleophilic substitution with ethyl bromide (EtBr), resulting in an alkylated beta-keto ester.

Finally, the alkylated beta-keto ester undergoes hydrolysis and decarboxylation in the presence of water (H2O) and sulfuric acid (H2SO4) with heat (Δ), leading to the formation of a ketone as the major organic product.