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

13. Alcohols and Carbonyl Compounds

Oxidizing and Reducing Agents

Organic Chemistry

13. Alcohols and Carbonyl Compounds

Oxidizing and Reducing Agents

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5:12 minutes

Problem 58e

Textbook Question

Draw the products of the following reactions. Indicate whether each reaction is an oxidation or a reduction.
e.

Verified step by step guidance

Step 1: Analyze the given reaction. The starting material is a methyl ester (cyclohexanecarboxylic acid methyl ester), and the reagents are lithium aluminum hydride (LiAlH4) followed by acid workup (H3O+). LiAlH4 is a strong reducing agent used to reduce esters to primary alcohols.

Step 2: Understand the mechanism. LiAlH4 donates hydride ions (H-) to the carbonyl carbon of the ester, breaking the C=O bond and forming an intermediate alkoxide. The methoxy group (-OCH3) is displaced as methanol during the reaction.

Step 3: After the reduction by LiAlH4, the intermediate alkoxide is protonated during the acid workup (H3O+), resulting in the formation of a primary alcohol. The ester group is completely reduced to an alcohol.

Step 4: Identify the product. The ester group (-COOCH3) in cyclohexanecarboxylic acid methyl ester is reduced to a primary alcohol (-CH2OH), resulting in cyclohexanemethanol as the product.

Step 5: Classify the reaction. Since the reaction involves the addition of hydrogen (reduction of the ester to an alcohol), it is classified as a reduction reaction.

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Key Concepts

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

Reduction Reactions

Reduction reactions involve the gain of electrons or hydrogen, or the loss of oxygen by a molecule. In organic chemistry, this often pertains to the conversion of carbonyl compounds (like aldehydes and ketones) into alcohols. The reaction shown in the image illustrates the reduction of a carbonyl compound using lithium aluminum hydride (LiAlH4), a strong reducing agent.

Lithium Aluminum Hydride (LiAlH4)

Lithium aluminum hydride is a powerful reducing agent commonly used in organic synthesis. It can reduce a variety of functional groups, including carbonyls and esters, to their corresponding alcohols. In the reaction depicted, LiAlH4 donates hydride ions (H-) to the carbonyl carbon, facilitating the reduction process.

Protonation of Alkoxides

After the reduction step, the alkoxide intermediate formed needs to be protonated to yield the final alcohol product. This is typically achieved by adding a proton source, such as water or an acid, as shown in the second step of the reaction. This step is crucial as it converts the alkoxide into a stable alcohol, completing the reduction process.

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Related Practice

Textbook Question

The intermediates for the oxidation of isopropanol to acetone are shown. Calculate oxidation numbers for the indicated atoms, then use them to determine in which step oxidation occurs.

(e)