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

Allylic Bromination

Organic Chemistry

11. Radical Reactions

Allylic Bromination

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2:40 minutes

Problem 31b

Textbook Question

What is the major product of the following reactions? Disregard stereoisomers:
b.

Verified step by step guidance

Step 1: Recognize the reagents and conditions. NBS (N-Bromosuccinimide) is used for allylic or benzylic bromination in the presence of a radical initiator, such as peroxide and heat.

Step 2: Identify the allylic position in the molecule. The allylic position is the carbon atom adjacent to the double bond in the cyclopentene structure.

Step 3: Understand the mechanism. The reaction proceeds via a radical mechanism. Peroxide and heat generate radicals, which abstract a hydrogen atom from the allylic position, forming an allylic radical.

Step 4: Bromine from NBS reacts with the allylic radical to form the major product. The bromine atom attaches to the allylic position, resulting in an allylic bromide.

Step 5: Consider resonance stabilization. The allylic radical is resonance-stabilized, so bromination can occur at either of the two equivalent allylic positions. Disregard stereoisomers as instructed.

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Key Concepts

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

Reaction Mechanisms

Understanding reaction mechanisms is crucial in organic chemistry as they describe the step-by-step process by which reactants transform into products. This includes identifying intermediates, transition states, and the movement of electrons. Familiarity with mechanisms helps predict the major products of reactions based on the stability of intermediates and the energy changes involved.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. Recognizing functional groups allows chemists to predict how a compound will react in a given reaction. Different functional groups can influence the reactivity and the type of products formed during chemical reactions.

Regioselectivity

Regioselectivity refers to the preference of a chemical reaction to occur at one location over another in a molecule. This concept is essential for predicting the major product of a reaction, as certain pathways may lead to more stable or favorable products. Understanding regioselectivity helps in determining which isomer will be formed when multiple possibilities exist.

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