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

Anti Markovnikov Addition of Br

Organic Chemistry

11. Radical Reactions

Anti Markovnikov Addition of Br

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3:46 minutes

Problem 22a(3,4)

Textbook Question

Draw the major product(s) of the reaction of 1-methylcyclohexene with the following reagents, disregarding stereoisomers:
3. HBr
4. HBr/peroxide

Verified step by step guidance

Identify the structure of 1-methylcyclohexene. It is a cyclohexene ring with a double bond and a methyl group attached to one of the carbons in the double bond.

For reaction 3 (HBr): Recognize that this is a hydrohalogenation reaction. The double bond will react with HBr, and the reaction will proceed via Markovnikov's rule. This means the hydrogen (H) will add to the carbon in the double bond with more hydrogens already attached, and the bromine (Br) will add to the carbon with fewer hydrogens.

Draw the intermediate carbocation formed during the reaction with HBr. The more stable carbocation (secondary or tertiary) will form, as carbocation stability influences the reaction pathway.

For reaction 4 (HBr/peroxide): Recognize that the presence of peroxide changes the reaction mechanism to a free radical addition. This reaction proceeds via anti-Markovnikov's rule, where the bromine (Br) adds to the carbon in the double bond with more hydrogens, and the hydrogen (H) adds to the carbon with fewer hydrogens.

Draw the major product(s) for both reactions, keeping in mind the regioselectivity (Markovnikov for HBr and anti-Markovnikov for HBr/peroxide). 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.

Electrophilic Addition Reactions

Electrophilic addition reactions involve the addition of an electrophile to a nucleophile, typically across a double bond. In the case of alkenes like 1-methylcyclohexene, the π bond acts as a nucleophile, reacting with electrophiles such as HBr. This process leads to the formation of a more stable carbocation intermediate, which can then react with a nucleophile to form the final product.

Markovnikov's Rule

Markovnikov's Rule states that in the addition of HX (where X is a halogen) to an alkene, the hydrogen atom will attach to the carbon with the greater number of hydrogen atoms already attached. This rule helps predict the major product of the reaction, as it favors the formation of the more stable carbocation, leading to the most substituted alkyl halide as the final product.

Radical Mechanism in Peroxide Reactions

The presence of peroxides in reactions with HBr leads to a radical mechanism, which differs from the typical electrophilic addition. In this case, the reaction proceeds via the formation of bromine radicals that add to the alkene, resulting in anti-Markovnikov products. This mechanism is crucial for understanding how the presence of peroxides alters the regioselectivity of the reaction.

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Related Practice

Textbook Question

Predict the product of the following alkene addition reactions.

(b)

Textbook Question

What alkyl halide will be obtained in greatest yield? Ignore stereoisomers.

Textbook Question

Draw the structures of four six-carbon alkenes that form the same product, whether they react with HBr in the presence of a peroxide or with HBr in the absence of a peroxide.

Textbook Question

What alkyl halide will be obtained in greatest yield? Ignore stereoisomers.

Textbook Question

What is the major product of the reaction of 2-methyl-2-butene with each of the following reagents?

c. HBr + peroxide

d. HCl + peroxide

Textbook Question

Predict the product(s) that would result when the alkenes shown here are allowed to react under the following conditions: (iii) HBr, H₂O₂

(b)

Textbook Question

Retrosynthetic analysis is the process of working backward to develop the synthesis of a new compound. In Chapter 10, we begin developing multistep syntheses in this manner. For now, try to work backward a single step by suggesting an alkene and a reagent that would give products (a)–(i). [Your answers should not include alkenes that undergo rearrangement to give the desired products.]

(d)

Textbook Question

What reagents are needed to carry out the following syntheses?

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