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

21. Aldehydes and Ketones: Nucleophilic Addition

Wolff Kishner Reduction

Organic Chemistry

21. Aldehydes and Ketones: Nucleophilic Addition

Wolff Kishner Reduction

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1:08 minutes

Problem 51a

Textbook Question

Show the product expected by the Wolff–Kishner reduction of the following aldehydes/ketones.
(a)

Verified step by step guidance

Identify the functional group in the given compound that will undergo the Wolff–Kishner reduction. In this case, it is the carbonyl group (C=O) of the ketone.

Understand that the Wolff–Kishner reduction is a method used to convert carbonyl groups into methylene groups (CH2) using hydrazine (H2NNH2) and a strong base like KOH under high temperature.

Recognize that the reaction involves the formation of a hydrazone intermediate, where the carbonyl oxygen is replaced by a hydrazine moiety, followed by the elimination of nitrogen gas (N2) to form the alkane.

Apply the Wolff–Kishner reduction to the given ketone. Replace the carbonyl group with a methylene group, effectively removing the oxygen and adding two hydrogen atoms to the carbonyl carbon.

Draw the final product structure, ensuring that the pyridine ring and the ethyl group remain unchanged, while the carbonyl carbon is now part of a methylene group, resulting in a fully saturated carbon chain.

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Key Concepts

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

Wolff–Kishner Reduction

The Wolff–Kishner reduction is a chemical reaction used to convert carbonyl compounds, such as aldehydes and ketones, into alkanes. This process involves the hydrazone formation followed by the treatment with a strong base, typically potassium hydroxide, and heating, which leads to the removal of nitrogen gas and the formation of the corresponding alkane.

Carbonyl Compounds

Carbonyl compounds are organic molecules that contain a carbon atom double-bonded to an oxygen atom (C=O). This functional group is characteristic of aldehydes and ketones, which differ in their structure; aldehydes have at least one hydrogen atom attached to the carbonyl carbon, while ketones have two carbon groups attached. Understanding their structure is crucial for predicting the outcome of reactions like the Wolff–Kishner reduction.

Hydrazones

Hydrazones are compounds formed by the reaction of hydrazine with carbonyl compounds, resulting in a C=N bond. In the context of the Wolff–Kishner reduction, the formation of a hydrazone intermediate is essential, as it stabilizes the carbonyl compound and facilitates the subsequent elimination of nitrogen gas, ultimately leading to the formation of the alkane product.

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