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

11. Radical Reactions

Free Radical Halogenation

Organic Chemistry

11. Radical Reactions

Free Radical Halogenation

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5:21 minutes

Problem 23

Textbook Question

Can you make a 1° bromoalkane like (3-bromopropyl)cyclopentane using alkane halogenation? Why or why not?

Verified step by step guidance

Understand the concept of alkane halogenation: Alkane halogenation is a reaction where a halogen (such as bromine) is added to an alkane, typically in the presence of heat or light, resulting in the substitution of a hydrogen atom with a halogen atom.

Identify the structure of the desired product: (3-bromopropyl)cyclopentane is a primary bromoalkane where a bromine atom is attached to the third carbon of a propyl group, which is itself attached to a cyclopentane ring.

Consider the mechanism of free radical halogenation: This process involves the formation of free radicals and typically results in the substitution of hydrogen atoms on the most accessible or most stable carbon, often leading to a mixture of products.

Evaluate the selectivity of bromination: Bromination is more selective than chlorination, favoring substitution at the most stable radical position, which is often a tertiary or secondary carbon rather than a primary carbon.

Conclude the feasibility: Since the desired product is a primary bromoalkane, and free radical halogenation tends to favor more stable radical positions, it is unlikely to selectively produce (3-bromopropyl)cyclopentane using simple alkane halogenation.

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Key Concepts

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

Alkane Halogenation

Alkane halogenation is a reaction where a halogen, such as bromine, reacts with an alkane in the presence of heat or light to form a haloalkane. This process typically involves the formation of free radicals and is not selective, often leading to a mixture of products. The lack of selectivity makes it challenging to produce a specific haloalkane, such as a 1° bromoalkane, without forming other isomers.

Radical Mechanism

The radical mechanism is a chain reaction process that involves the formation, propagation, and termination of free radicals. In alkane halogenation, the initiation step generates radicals, which then react with alkanes to form new radicals and haloalkanes. This mechanism is non-selective, often leading to multiple substitution products, which complicates the synthesis of specific haloalkanes like 1° bromoalkanes.

Selectivity in Halogenation

Selectivity in halogenation refers to the preference for halogen atoms to substitute hydrogen atoms at specific positions on the carbon chain. In the case of bromination, the reaction is more selective than chlorination, favoring the formation of more stable radicals. However, achieving exclusive formation of a 1° bromoalkane is difficult due to competing reactions that can lead to secondary or tertiary bromoalkanes, especially in complex molecules like (3-bromopropyl)cyclopentane.