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

8. Elimination Reactions

SN1 SN2 E1 E2 Chart (Big Daddy Flowchart)

Organic Chemistry

8. Elimination Reactions

SN1 SN2 E1 E2 Chart (Big Daddy Flowchart)

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8:53 minutes

Problem 68

Textbook Question

The following chlorocyclohexane undergoes neither Sₙ2 nor E2 under the conditions shown. Why?

Verified step by step guidance

Analyze the structure of chlorocyclohexane: Chlorocyclohexane is a cyclohexane ring with a chlorine atom attached to one of the carbons. The chlorine atom is a good leaving group, but the reaction mechanism depends on the conditions provided.

Understand the Sₙ2 mechanism: The Sₙ2 mechanism requires a strong nucleophile and a substrate that is not sterically hindered. In the case of chlorocyclohexane, the cyclohexane ring creates steric hindrance, especially if the chlorine is in the equatorial position, making it difficult for the nucleophile to attack the carbon bearing the chlorine.

Understand the E2 mechanism: The E2 mechanism requires a strong base and an anti-periplanar arrangement of the β-hydrogen and the leaving group. In chlorocyclohexane, the anti-periplanar geometry may not be achievable due to the conformational constraints of the cyclohexane ring, especially if the chlorine is in the equatorial position.

Consider the reaction conditions: If the conditions provided do not include a strong nucleophile (for Sₙ2) or a strong base (for E2), neither mechanism will proceed. Additionally, steric hindrance and conformational constraints further inhibit these reactions.

Conclude why neither mechanism occurs: The combination of steric hindrance, conformational constraints, and potentially unsuitable reaction conditions prevents both the Sₙ2 and E2 mechanisms from occurring in this case.

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Key Concepts

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

Sₙ2 Mechanism

The Sₙ2 mechanism is a bimolecular nucleophilic substitution reaction where a nucleophile attacks an electrophile, leading to the simultaneous displacement of a leaving group. This reaction typically occurs in primary or secondary substrates due to steric accessibility. In the case of chlorocyclohexane, steric hindrance from the cyclohexane ring can prevent effective nucleophilic attack, making Sₙ2 unlikely.

E2 Mechanism

The E2 mechanism is a concerted elimination reaction where a base abstracts a proton while a leaving group departs, resulting in the formation of a double bond. This reaction is favored in secondary and tertiary substrates due to steric factors. In chlorocyclohexane, the ring structure may hinder the necessary anti-periplanar arrangement of the leaving group and the hydrogen, thus inhibiting E2 reactivity.

Steric Hindrance

Steric hindrance refers to the prevention of chemical reactions due to the spatial arrangement of atoms within a molecule. In bulky molecules like chlorocyclohexane, the presence of large groups can obstruct the approach of nucleophiles or bases, making reactions like Sₙ2 and E2 less favorable. Understanding steric hindrance is crucial for predicting the reactivity of organic compounds.

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