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

10. Addition Reactions

Hydrohalogenation

Organic Chemistry

10. Addition Reactions

Hydrohalogenation

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1:25 minutes

Problem 36a

Textbook Question

(a) How would you convert propene to 2-bromopropane?

Verified step by step guidance

Identify the starting material (propene) and the desired product (2-bromopropane). Propene is an alkene, and the reaction involves adding a bromine atom to the molecule.

Recognize that this is an electrophilic addition reaction, specifically hydrohalogenation, where HBr is used to add a hydrogen atom and a bromine atom across the double bond of the alkene.

Apply Markovnikov's rule to determine the regioselectivity of the reaction. According to Markovnikov's rule, the hydrogen atom from HBr will add to the carbon of the double bond that already has more hydrogen atoms, while the bromine atom will add to the carbon with fewer hydrogen atoms.

Write the reaction mechanism: (1) The π electrons of the double bond attack the hydrogen atom of HBr, forming a carbocation intermediate on the more substituted carbon. (2) The bromide ion (Br⁻) then attacks the carbocation, resulting in the formation of 2-bromopropane.

Verify the product structure to ensure that the bromine atom is attached to the second carbon of the original propene molecule, yielding 2-bromopropane as the final product.

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Key Concepts

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

Electrophilic Addition

Electrophilic addition is a fundamental reaction mechanism in organic chemistry where an electrophile reacts with a nucleophile, typically involving alkenes. In the case of propene, the double bond acts as a nucleophile, allowing it to react with an electrophile such as bromine. This process results in the formation of a more stable product, in this case, 2-bromopropane.

Markovnikov's Rule

Markovnikov's Rule states that when HX (where X is a halogen) is added to an alkene, the hydrogen atom will attach to the carbon with the greater number of hydrogen atoms already attached. This principle helps predict the major product of the reaction. For propene, this means that bromine will add to the more substituted carbon, leading to the formation of 2-bromopropane.

Stereochemistry of Addition Reactions

Stereochemistry refers to the spatial arrangement of atoms in molecules and how this affects their chemical behavior. In the addition of bromine to propene, the stereochemical outcome can lead to different isomers, including enantiomers or diastereomers. Understanding the stereochemical implications is crucial for predicting the properties and reactivity of the resulting 2-bromopropane.

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Related Practice

Textbook Question

When 3-methyl-1-butene reacts with HBr, two alkyl halides are formed: 2-bromo-3-methylbutane and 2-bromo-2-methylbutane. Propose a mechanism that explains the formation of these two products.