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

7. Substitution Reactions

Substitution Comparison

Organic Chemistry

7. Substitution Reactions

Substitution Comparison

Previous problemNext problem

5:03 minutes

Problem 66

Textbook Question

Give a mechanism for the following substitution and elimination reactions.
(a)

Verified step by step guidance

Identify the type of substitution or elimination reaction. Determine whether the reaction is SN1, SN2, E1, or E2 based on the substrate (primary, secondary, or tertiary alkyl halide), the nucleophile/base strength, and the solvent (polar protic or aprotic).

For substitution reactions: If the reaction is SN1, draw the mechanism starting with the formation of a carbocation intermediate after the leaving group departs. If the reaction is SN2, show a single concerted step where the nucleophile attacks the electrophilic carbon from the opposite side of the leaving group, leading to inversion of configuration.

For elimination reactions: If the reaction is E1, show the formation of a carbocation intermediate after the leaving group departs, followed by the removal of a β-hydrogen by the base to form a double bond. If the reaction is E2, depict a single concerted step where the base abstracts a β-hydrogen while the leaving group departs, forming a double bond.

Consider regioselectivity and stereoselectivity: For elimination reactions, apply Zaitsev's rule (the more substituted alkene is favored) unless steric hindrance or a bulky base favors the Hofmann product. For substitution reactions, consider stereochemical outcomes (e.g., inversion in SN2).

Draw the complete step-by-step mechanism for the reaction, including all intermediates, transition states, and curved arrows to indicate electron flow. Ensure that all charges and lone pairs are properly accounted for in the mechanism.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

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

Nucleophilic Substitution

Nucleophilic substitution is a fundamental reaction in organic chemistry where a nucleophile attacks an electrophile, resulting in the replacement of a leaving group. This process can occur via two main mechanisms: SN1, which involves a two-step process with a carbocation intermediate, and SN2, which is a one-step process where the nucleophile attacks the electrophile simultaneously as the leaving group departs. Understanding the conditions that favor each mechanism is crucial for predicting the outcome of substitution reactions.

Elimination Reactions

Elimination reactions involve the removal of a small molecule, typically water or hydrogen halide, from a larger molecule, resulting in the formation of a double bond. The two primary types are E1, which is a two-step process involving a carbocation intermediate, and E2, which is a concerted one-step process where the base abstracts a proton while the leaving group departs. The choice between substitution and elimination often depends on the structure of the substrate and the reaction conditions.

Reaction Mechanism

A reaction mechanism is a detailed description of the step-by-step process by which reactants are converted into products in a chemical reaction. It includes the identification of intermediates, transition states, and the order of bond breaking and forming. Understanding the mechanism is essential for predicting the products of a reaction, as well as the conditions under which different pathways (substitution vs. elimination) are favored.

Watch next

Master How do we predict if the mechanism is SN1 or SN2? with a bite sized video explanation from Johnny

Start learning