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

E1 Reaction

Organic Chemistry

8. Elimination Reactions

E1 Reaction

Previous problemNext problem

3:27 minutes

Problem 84a,b

Textbook Question

Draw the major product obtained when an alkyl halide in [PROBLEM 9-83] undergoes an E1 reaction.
a.
b.

Verified step by step guidance

Step 1: Identify the alkyl halide structure provided in the images. The first image shows 2-bromo-2-methylbutane, and the second image shows cyclohexyl chloride. Both are alkyl halides capable of undergoing an E1 elimination reaction.

Step 2: Recall the mechanism of an E1 reaction. E1 elimination involves two steps: (1) the departure of the leaving group (e.g., Br or Cl) to form a carbocation intermediate, and (2) the elimination of a proton from a β-carbon to form a double bond.

Step 3: Analyze the stability of the carbocation intermediate formed after the leaving group departs. For 2-bromo-2-methylbutane, the carbocation formed is tertiary, which is highly stable. For cyclohexyl chloride, the carbocation formed is secondary, which is moderately stable.

Step 4: Determine the β-hydrogens available for elimination. In 2-bromo-2-methylbutane, elimination can occur at either of the β-carbons adjacent to the carbocation, leading to the formation of an alkene. For cyclohexyl chloride, elimination occurs at one of the β-carbons in the cyclohexane ring, forming a double bond within the ring.

Step 5: Apply Zaitsev's rule to predict the major product. Zaitsev's rule states that the most substituted alkene is the major product. For 2-bromo-2-methylbutane, the major product is 2-methyl-2-butene. For cyclohexyl chloride, the major product is cyclohexene.

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.

E1 Reaction Mechanism

The E1 (unimolecular elimination) reaction is a two-step process where the first step involves the formation of a carbocation intermediate after the leaving group departs. The second step involves the elimination of a proton from a neighboring carbon, leading to the formation of a double bond. This mechanism typically occurs with tertiary alkyl halides due to their stability in forming carbocations.

Carbocation Stability

Carbocation stability is crucial in determining the outcome of E1 reactions. Tertiary carbocations are more stable than secondary or primary ones due to hyperconjugation and inductive effects from surrounding alkyl groups. The stability of the carbocation influences the rate of the reaction and the major product formed, as more stable carbocations are favored in the reaction pathway.

Regioselectivity in Elimination Reactions

Regioselectivity refers to the preference for the formation of one constitutional isomer over others in a chemical reaction. In E1 reactions, the elimination can lead to different alkenes depending on which hydrogen is removed. The more substituted alkene is typically favored due to greater stability, following Zaitsev's rule, which states that the more substituted alkene is the major product in elimination reactions.

Watch next

Master Drawing the E1 Mechanism. with a bite sized video explanation from Johnny

Start learning