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

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2:52 minutes

Problem 38a

Textbook Question

Practice your electron-pushing skills by drawing a mechanism for the following E1 reactions.
(a)

Verified step by step guidance

Identify the substrate in the reaction. In an E1 reaction, the substrate is typically a secondary or tertiary alkyl halide or alcohol, which can form a stable carbocation intermediate.

Determine the leaving group. In an E1 reaction, the leaving group departs first, forming a carbocation. Use curved arrows to show the movement of electrons from the bond between the carbon and the leaving group to the leaving group itself.

Analyze the stability of the carbocation formed. If the initial carbocation is not the most stable form, consider possible carbocation rearrangements (e.g., hydride shifts or alkyl shifts) to form a more stable carbocation.

Identify the β-hydrogens on the carbocation. These are hydrogens attached to carbons adjacent to the carbocation. Use curved arrows to show the base abstracting a β-hydrogen, and the electrons from the C-H bond forming a π-bond (double bond) between the α-carbon (carbocation) and the β-carbon.

Draw the final product, which is the alkene formed after the elimination step. If multiple β-hydrogens are available, consider Zaitsev's rule, which predicts that the more substituted alkene 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.

E1 Mechanism

The E1 mechanism, or unimolecular elimination, involves two main steps: the formation of a carbocation intermediate followed by the loss of a leaving group to form a double bond. This process typically occurs in polar protic solvents and is favored by tertiary substrates due to their ability to stabilize the carbocation. Understanding the E1 mechanism is crucial for predicting the products of elimination reactions.

Carbocation Stability

Carbocation stability is a key factor in E1 reactions, as the rate-determining step involves the formation of a carbocation. Tertiary carbocations are more stable than secondary or primary ones due to hyperconjugation and inductive effects from surrounding alkyl groups. Recognizing the stability of different carbocations helps in predicting the pathway and products of elimination reactions.

Electron-Pushing Curved Arrows

Electron-pushing curved arrows are a fundamental notation in organic chemistry used to illustrate the movement of electrons during chemical reactions. In the context of E1 reactions, these arrows show how electrons are transferred from nucleophiles to electrophiles, and how bonds are formed or broken. Mastery of this notation is essential for accurately depicting reaction mechanisms and understanding the flow of electrons.

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