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

24. Enolate Chemistry: Reactions at the Alpha-Carbon

Hell-Volhard-Zelinski Reaction

Organic Chemistry

24. Enolate Chemistry: Reactions at the Alpha-Carbon

Hell-Volhard-Zelinski Reaction

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2:46 minutes

Problem 71b

Textbook Question

Show how you would accomplish the following conversions in good yields. You may use any necessary reagents.
(b)

Verified step by step guidance

Identify the starting material as cyclohexanecarboxylic acid and the product as bromocyclohexanecarboxylic acid, where a bromine atom is added to the alpha-carbon (the carbon adjacent to the carboxylic acid group).

Recognize that this transformation involves alpha-bromination of a carboxylic acid. This can be achieved using the Hell-Volhard-Zelinsky (HVZ) reaction, which selectively brominates the alpha-carbon of carboxylic acids.

First, treat the carboxylic acid with phosphorus tribromide (PBr₃) to form the corresponding acyl bromide. This step activates the carboxylic acid for the subsequent reaction.

Next, add bromine (Br₂) to the reaction mixture. The bromine reacts with the acyl bromide to brominate the alpha-carbon via an enol intermediate.

Finally, hydrolyze the acyl bromide back to the carboxylic acid by adding water, regenerating the carboxylic acid group and yielding the desired brominated product.

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Key Concepts

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

Reaction Mechanisms

Understanding reaction mechanisms is crucial in organic chemistry as it describes the step-by-step process by which reactants transform into products. This includes identifying intermediates, transition states, and the role of catalysts. A clear grasp of mechanisms helps predict the outcome of reactions and the conditions needed for successful conversions.

Reagents and Conditions

Different organic reactions require specific reagents and conditions to proceed effectively. Knowledge of common reagents, such as acids, bases, oxidizing agents, and reducing agents, is essential. Additionally, understanding factors like temperature, pressure, and solvent choice can significantly influence reaction yields and selectivity.

Stereochemistry

Stereochemistry involves the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. In many organic reactions, the formation of stereoisomers can lead to different products with distinct properties. Recognizing stereochemical outcomes is vital for predicting the success of conversions and ensuring desired product formation.

Show how you would accomplish the following conversions in good yields. You may use any necessary reagents.(b)

Key Concepts

Reaction Mechanisms

Reagents and Conditions

Stereochemistry

Show how you would accomplish the following conversions in good yields. You may use any necessary reagents.
(b)