Which of the following is NOT a plausible intermediate in the following reaction? <img src="https://media.pearsoncmg.com/ph/esm/ecs_mullins_organic1e/msa/content/practice-test/img/Ch08_Q04_QT.jpg" alt="The figure illustrates a reaction in which the product has to be determined. The reaction contains two reactants. The first reactant has the following structure: A 5-carbon pentagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. C 2 is single bonded to C H 3 above in the form of a line. C 2 is single bonded on the upper right to C 1 of a 2-carbon alkene chain depicted as a line structure in the form of two parallel lines. The second reactant is H, single bond, B r written over the reaction arrow." />

A 5-carbon pentagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. C 2 is single bonded to C H 3 above in the form of a line and single bonded on the upper right to C 1 of a 2-carbon alkane chain depicted as a line structure using 1 line. C 2 of the ring carries a positive charge." />

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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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Multiple Choice

Which of the following is NOT a plausible intermediate in the following reaction?

The figure illustrates the structure of an ion. A 5-carbon pentagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. C 2 is single bonded to C 2 of a 3-carbon alkane chain depicted as a line structure using 2 zigzag lines. C 2 of the ring carries a positive charge.

The figure illustrates the structure of an ion. A 6-carbon hexagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. C 2 carries a positive charge and is single bonded to C H 3 in the form of a line. C 3 is single bonded to C H 3 in the form of a line.

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Verified step by step guidance

Identify the starting material and the reagent: The starting material is a cyclopentane ring with an isopropyl group and a vinyl group attached. The reagent is HBr.

Understand the reaction mechanism: The reaction of an alkene with HBr typically follows a Markovnikov addition mechanism, where the hydrogen atom from HBr adds to the less substituted carbon of the double bond, forming a carbocation intermediate.

Determine the possible carbocation intermediates: The initial addition of H+ to the alkene can lead to different carbocation intermediates depending on which carbon the hydrogen adds to.

Evaluate the stability of each carbocation: Carbocation stability is influenced by factors such as hyperconjugation and resonance. Tertiary carbocations are more stable than secondary, which are more stable than primary.

Analyze the given structures: Compare the given carbocation structures to determine which one is not plausible based on the expected reaction mechanism and carbocation stability. Consider whether any rearrangements could lead to a more stable carbocation.