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

12. Alcohols, Ethers, Epoxides and Thiols

Leaving Group Conversions - SOCl2 and PBr3

Organic Chemistry

12. Alcohols, Ethers, Epoxides and Thiols

Leaving Group Conversions - SOCl2 and PBr3

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1:58 minutes

Problem 35a

Textbook Question

Provide the alcohol that would be used to make the bromoalkanes shown using PBr₃.
(a)

Verified step by step guidance

Identify the bromoalkane structure given in the problem. This will help determine the corresponding alcohol needed for the reaction.

Understand that PBr₃ (phosphorus tribromide) is used to convert alcohols into bromoalkanes by substituting the hydroxyl group (-OH) with a bromine atom (Br).

Determine the position of the bromine atom in the bromoalkane. This position corresponds to where the hydroxyl group was in the original alcohol.

Draw the structure of the alcohol by replacing the bromine atom in the bromoalkane with a hydroxyl group (-OH). Ensure that the carbon skeleton remains unchanged.

Verify the structure of the alcohol by considering the reaction mechanism of PBr₃, which involves the formation of a phosphite ester intermediate and subsequent substitution to form the bromoalkane.

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Key Concepts

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

Alcohols

Alcohols are organic compounds characterized by the presence of a hydroxyl group (-OH) attached to a carbon atom. They serve as key starting materials in various chemical reactions, including the formation of bromoalkanes. Understanding the structure and reactivity of alcohols is essential for predicting the outcome of reactions involving PBr₃.

Bromoalkanes

Bromoalkanes, also known as alkyl bromides, are organic compounds where a bromine atom is bonded to an alkyl group. They are typically synthesized from alcohols through substitution reactions using reagents like PBr₃. Recognizing the structure of bromoalkanes helps in identifying the corresponding alcohol precursor needed for their synthesis.

PBr₃ Reaction Mechanism

Phosphorus tribromide (PBr₃) is a reagent used to convert alcohols into bromoalkanes via a substitution reaction. The mechanism involves the formation of an intermediate where the hydroxyl group is replaced by a bromine atom. Understanding this mechanism is crucial for determining which alcohol can be transformed into a specific bromoalkane using PBr₃.

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Related Practice

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (iii) SOCl₂ , NEt₃. If no reaction occurs, write 'no reaction.'

(a)

Multiple Choice

Predict the major, organic product for the following reaction.

Textbook Question

Write balanced equations for the three preceding reactions.

Textbook Question

Two products are observed in the following reaction.

a. Suggest a mechanism to explain how these two products are formed.

b. Your mechanism for part (a) should be different from the usual mechanism of the reaction of SOCl₂ with alcohols. Explain why the reaction follows a different mechanism in this case.

Textbook Question

Provide the alcohol that would be used to make the bromoalkanes shown using PBr₃.

(b)

Textbook Question

Provide the alcohol that would be used to make the bromoalkanes shown using PBr₃.

(c)

Textbook Question

Besides PBr₃. and SOCl₂ , there are other ways of synthesizing haloalkanes. One such way is shown. Provide an arrow-pushing mechanism that rationalizes formation of the chloroalkane. [Hint: Dimethyl sulfide is a good nucleophile and Cl₂ is an electrophile. Start by reacting those two together.]

Textbook Question

Identify the reagent that should be used to obtain each stereochemical outcome shown.

(a)

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