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

19. Reactions of Aromatics: EAS and Beyond

EAS:Retrosynthesis

Organic Chemistry

19. Reactions of Aromatics: EAS and Beyond

EAS:Retrosynthesis

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4:15 minutes

Problem 78b

Textbook Question

b. Describe two ways the following reaction can be carried out:

Verified step by step guidance

Step 1: Analyze the reaction. The starting material is a ketone (2-pentanone), and the product is an alkane (pentane). This indicates that the reaction involves the reduction of the carbonyl group to a hydrocarbon, likely through a process such as complete reduction or deoxygenation.

Step 2: Method 1 - Clemmensen Reduction. This method uses zinc amalgam (Zn(Hg)) and concentrated hydrochloric acid (HCl) to reduce the ketone to an alkane. The acidic conditions facilitate the removal of the oxygen atom from the carbonyl group.

Step 3: Method 2 - Wolff-Kishner Reduction. This method involves hydrazine (N₂H₄) and a strong base such as potassium hydroxide (KOH) under high temperatures. The hydrazine reacts with the ketone to form a hydrazone intermediate, which is then decomposed to yield the alkane.

Step 4: Compare the two methods. Clemmensen Reduction is typically used for compounds stable under acidic conditions, while Wolff-Kishner Reduction is preferred for compounds stable under basic conditions and high temperatures.

Step 5: Choose the appropriate method based on the substrate's stability and reaction conditions. For example, if the substrate is sensitive to acid, Wolff-Kishner Reduction would be the better choice.

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Key Concepts

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

Electrophilic Aromatic Substitution (EAS)

Electrophilic Aromatic Substitution is a fundamental reaction in organic chemistry where an electrophile replaces a hydrogen atom on an aromatic ring. This process typically involves the formation of a sigma complex, where the aromaticity is temporarily lost, followed by deprotonation to restore aromaticity. Understanding EAS is crucial for predicting the outcomes of reactions involving aromatic compounds.

Retrosynthetic Analysis

Retrosynthetic analysis is a strategy used in organic synthesis to break down complex molecules into simpler precursors. By working backward from the target molecule, chemists can identify potential starting materials and reaction pathways. This concept is essential for designing efficient synthetic routes and understanding how to achieve the desired product from given reactants.

Reaction Mechanisms

A reaction mechanism describes the step-by-step sequence of elementary reactions that occur during a chemical transformation. It provides insight into how reactants are converted into products, including the intermediates formed and the energy changes involved. Familiarity with reaction mechanisms is vital for predicting reaction outcomes and optimizing conditions for desired transformations.

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