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)

Previous problemNext problem

Problem 90b

Textbook Question

Identify whether each of the following reactions proceed by an S_N1, S_N2, E1, or E2 mechanism.
(b)

Verified step by step guidance

Step 1: Analyze the substrate structure. The substrate contains a sulfonate leaving group attached to a secondary carbon. Sulfonates are excellent leaving groups, making the substrate prone to elimination or substitution reactions.

Step 2: Examine the base and solvent. The base is sodium tert-butoxide (NaO-tBu), which is a strong, bulky base. The solvent is tert-butanol (t-BuOH), which is protic. Bulky bases favor elimination reactions, particularly E2 mechanisms, because steric hindrance makes substitution less likely.

Step 3: Consider the reaction conditions. The strong base and protic solvent suggest that elimination is favored over substitution. The bulky nature of the base further supports an E2 mechanism, as it can abstract a proton from a β-carbon without requiring the formation of a carbocation intermediate.

Step 4: Evaluate the stereochemistry and regiochemistry of the elimination. In an E2 mechanism, the proton abstraction and leaving group departure occur simultaneously in a concerted process. The reaction will likely follow Zaitsev's rule, favoring the formation of the more substituted alkene as the major product.

Step 5: Conclude the mechanism. Based on the substrate, base, solvent, and reaction conditions, this reaction proceeds via an E2 mechanism.

Verified video answer for a similar problem:

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

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 Mechanisms

Nucleophilic substitution reactions can occur via two primary mechanisms: SN1 and SN2. SN1 is a two-step process where the leaving group departs first, forming a carbocation intermediate, followed by nucleophilic attack. In contrast, SN2 is a one-step mechanism where the nucleophile attacks the substrate simultaneously as the leaving group departs, leading to a concerted reaction.

Elimination Reactions

Elimination reactions can also occur through two mechanisms: E1 and E2. E1 involves a two-step process similar to SN1, where the leaving group first forms a carbocation, followed by the removal of a proton to form a double bond. E2 is a concerted mechanism where the base removes a proton while the leaving group departs, resulting in the formation of a double bond in a single step.

Factors Influencing Mechanism Choice

The choice between SN1, SN2, E1, and E2 mechanisms depends on several factors, including the structure of the substrate (primary, secondary, or tertiary), the strength and concentration of the nucleophile or base, and the solvent used. Polar protic solvents favor SN1 and E1 mechanisms, while polar aprotic solvents favor SN2 and E2 mechanisms due to their ability to stabilize ions and facilitate nucleophilic attack.

Watch next

Master Overview of the flowchart. with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

For which of the following reactions would you expect elimination to be more favored than substitution?

(e)

Textbook Question

For each pair, choose the haloalkane that would react most quickly in an S_N1 or E1 reaction.

(a)

Textbook Question

Predict the product(s) that would result when the following molecules are allowed to react under the following conditions: (v) H₂O; (vi) NaOH, H₂O. If there is no reaction, write 'no reaction.'

(f)

Textbook Question

Identify whether each of the following reactions proceed by an S_N1, S_N2, E1, or E2 mechanism.

(c)

Textbook Question

For which of the following reactions would you expect elimination to be more favored than substitution?

(a)

Textbook Question

For which of the following reactions would you expect elimination to be more favored than substitution?

(d)

Textbook Question

When the following compound undergoes solvolysis in ethanol, three products are obtained. Propose a mechanism to account for the formation of these products.

Textbook Question

Draw the substitution and elimination products for the following reactions, showing the configuration of each product:

c. 1-chloro-1-methylcyclohexane + CH₃O⁻

d. 1-chloro-1-methylcyclohexane + CH₃OH

Show more practices