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

Protecting Alcohols from Organometallics

Organic Chemistry

13. Alcohols and Carbonyl Compounds

Protecting Alcohols from Organometallics

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9:14 minutes

Problem 43c

Textbook Question

Give the structures of the intermediates represented by letters O, P, and Q in this synthesis.

Verified step by step guidance

Step 1: Analyze the starting material and the first reaction. The starting material is an ester (methyl 3-phenylpropanoate). Reaction with LiAlH4 in ether reduces the ester to a primary alcohol. The intermediate J is therefore the corresponding primary alcohol, 3-phenylpropanol.

Step 2: Examine the conversion of J to K. The alcohol (J) is oxidized using NaOCl and TEMPO, which selectively oxidizes primary alcohols to aldehydes. Thus, intermediate K is 3-phenylpropanal.

Step 3: Analyze the reaction of J with TsCl and pyridine. This reaction converts the hydroxyl group of J into a tosylate group, forming intermediate L. Tosylates are good leaving groups, facilitating further reactions.

Step 4: Examine the reaction of L with KO-tBu. This is an elimination reaction where the tosylate group is eliminated, forming an alkene. Intermediate M is therefore 3-phenylpropene.

Step 5: Analyze the reaction of M with Br2 and H2O. This is a bromohydrin formation reaction, where the alkene reacts with bromine in water to form a bromohydrin. Intermediate N is 1-bromo-2-hydroxy-3-phenylpropane.

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Key Concepts

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

Synthesis Pathways

Synthesis pathways illustrate the step-by-step transformation of reactants into products through various intermediates. Understanding these pathways is crucial for identifying the structures of intermediates, as each step often involves specific reagents and conditions that dictate the outcome of the reaction.

Reagents and Their Functions

Different reagents play specific roles in organic reactions, such as reducing agents, oxidizing agents, or catalysts. For instance, LiAlH4 is a strong reducing agent used to convert carbonyl compounds to alcohols, while TsCl is used for activating alcohols for further reactions. Recognizing the function of each reagent helps in predicting the structure of intermediates.

Functional Group Transformations

Functional group transformations involve the conversion of one functional group into another, which is a common theme in organic synthesis. For example, the conversion of an alcohol to a carbonyl compound or vice versa is essential for understanding the intermediates in the synthesis pathway. Familiarity with these transformations aids in deducing the structures of intermediates labeled in the synthesis.

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