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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5:43 minutes

Problem 25c,d

Textbook Question

For each reaction, decide whether substitution or elimination (or both) is possible, and predict the products you expect. Label the major products.
c. chlorocyclohexane+NaOCH₃in CH₃OH
d. chlorocyclohexane + NaOC(CH₃)₃ in (CH₃)₃COH

Verified step by step guidance

Step 1: Analyze the substrate (chlorocyclohexane) in both reactions. Chlorocyclohexane is a secondary alkyl halide, which can undergo both substitution (SN1 or SN2) and elimination (E1 or E2) reactions depending on the reaction conditions.

Step 2: For reaction (c) with NaOCH3 in CH3OH, identify the base/nucleophile and solvent. NaOCH3 is a strong nucleophile and a strong base, while CH3OH is a polar protic solvent. This setup favors both SN2 and E2 mechanisms. Predict the products: (1) For SN2, substitution of the chlorine atom with -OCH3 will occur. (2) For E2, elimination will lead to the formation of a cyclohexene product. The major product will depend on the reaction conditions, but E2 is often favored with strong bases.

Step 3: For reaction (d) with NaOC(CH3)3 in (CH3)3COH, identify the base/nucleophile and solvent. NaOC(CH3)3 is a bulky, strong base, and (CH3)3COH is a polar protic solvent. Bulky bases favor elimination (E2) over substitution due to steric hindrance. Predict the product: elimination will lead to the formation of cyclohexene as the major product.

Step 4: Consider the regioselectivity of the elimination reactions. In both cases, the elimination will follow Zaitsev's rule, where the more substituted alkene is the major product. For cyclohexane derivatives, this typically results in a single product (cyclohexene) due to the symmetry of the ring.

Step 5: Summarize the major products for each reaction. For reaction (c), both substitution (SN2) and elimination (E2) products are possible, with the major product depending on the reaction conditions. For reaction (d), elimination (E2) is the dominant pathway, and cyclohexene is the major product.

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Key Concepts

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

Nucleophilic Substitution Reactions

Nucleophilic substitution reactions involve the replacement of a leaving group (like a halide) by a nucleophile. In this context, the nucleophile is the alkoxide ion (NaOCH3 or NaOC(CH3)3). Understanding the mechanism (SN1 or SN2) is crucial, as it influences the reaction pathway and the structure of the products formed.

Elimination Reactions

Elimination reactions involve the removal of a leaving group and a hydrogen atom, resulting in the formation of a double bond. The two main types are E1 and E2 mechanisms. The choice between substitution and elimination often depends on factors such as the strength of the base, the structure of the substrate, and the reaction conditions.

Reaction Conditions and Solvent Effects

The solvent and reaction conditions significantly influence whether substitution or elimination occurs. Polar protic solvents favor SN1 and E1 mechanisms, while polar aprotic solvents favor SN2 and E2 mechanisms. In the given reactions, the choice of methanol and tert-butanol as solvents will affect the reactivity and the predominant pathway taken by the nucleophile.

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