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

6:13 minutes

Problem 54d

Textbook Question

Write a balanced equation for each reaction, showing the major product you expect.
(d)

Verified step by step guidance

Step 1: Identify the type of reaction. The presence of NaOH and heat suggests an elimination reaction (E2 mechanism), where the alkyl halide undergoes dehydrohalogenation to form an alkene.

Step 2: Analyze the structure of the starting material, CH3CH(CH3)C(CH3)2Br. The bromine atom is attached to a tertiary carbon, which is highly favorable for elimination reactions due to steric hindrance.

Step 3: Determine the possible β-hydrogens available for elimination. The β-hydrogens are located on the carbons adjacent to the carbon bonded to the bromine atom. In this case, there are β-hydrogens on the methyl groups and the ethyl group.

Step 4: Apply Zaitsev's rule to predict the major product. Zaitsev's rule states that the most substituted alkene will be the major product. Elimination of a β-hydrogen from the ethyl group will result in the formation of the more substituted alkene.

Step 5: Write the balanced equation for the reaction. The bromine atom is removed, and a double bond is formed between the α-carbon (the carbon bonded to bromine) and the β-carbon (the carbon from which the hydrogen is eliminated). The major product is the more substituted alkene.

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 Reactions

Nucleophilic substitution reactions involve the replacement of a leaving group (like Br) by a nucleophile (like OH- from NaOH). These reactions can proceed via two main mechanisms: SN1, which is unimolecular and involves a carbocation intermediate, and SN2, which is bimolecular and involves a direct attack by the nucleophile. The choice of mechanism depends on factors such as substrate structure and the strength of the nucleophile.

Carbocation Stability

Carbocation stability is crucial in determining the pathway of nucleophilic substitution reactions. Tertiary carbocations are more stable than secondary or primary due to hyperconjugation and inductive effects from surrounding alkyl groups. In the given reaction, the presence of multiple alkyl groups adjacent to the carbocation can favor the SN1 mechanism, leading to the formation of a more stable intermediate before the nucleophile attacks.

Reaction Conditions and Heat

The reaction conditions, including the use of heat, can influence the outcome of nucleophilic substitution reactions. Heating can favor elimination reactions or promote the formation of more stable products. In this case, heating the reaction with NaOH may enhance the likelihood of an SN1 pathway, allowing for the formation of a stable carbocation and subsequent product formation, rather than competing elimination reactions.

Watch next

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

Start learning

Related Videos

Related Practice

Textbook Question

After a proton is removed from the OH group, which compound in each pair forms a cyclic ether more rapidly?

Textbook Question

Pure (S)-2-bromo-2-fluorobutane reacts with methoxide ion in methanol to give a mixture of (S)-2-fluoro-2-methoxybutane and three fluoroalkenes.

b. Propose a mechanism to show how (S)-2-bromo-2-fluorobutane reacts to give (S)-2-fluoro-2-methoxybutane. Has this reaction gone with retention or inversion of configuration?

Textbook Question

Pure (S)-2-bromo-2-fluorobutane reacts with methoxide ion in methanol to give a mixture of (S)-2-fluoro-2-methoxybutane and three fluoroalkenes.

a. Use mechanisms to show which three fluoroalkenes are formed.

Textbook Question

Propose mechanisms for the following reactions. Additional products may be formed, but your mechanism only needs to explain the products shown.

(a)

Textbook Question

Predict the products and mechanisms of the following reactions. When more than one product or mechanism is possible, explain which are most likely.

h. 1-bromo-1-methylcyclopentane heated in methanol

Textbook Question

Predict the products and mechanisms of the following reactions. When more than one product or mechanism is possible, explain which are most likely.

g. 1−bromo−1−methylcyclopentane + NaOEt in ethanol

Textbook Question

Predict the major and minor elimination products of the following proposed reactions (ignoring any possible substitutions for now). In each case, explain whether you expect the mechanism of the elimination to be E1 or E2.

(a)

Textbook Question

For each reaction, decide whether substitution or elimination (or both) is possible, and predict the products you expect. Label the major products.

a. 1−bromo−1−methylcyclohexane + NaOH in acetone

Show more practices