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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4:54 minutes

Problem 47a

Textbook Question

Predict the product of the following rearrangement-prone E1 eliminations.
(a)

Verified step by step guidance

Identify the substrate structure and determine if it is prone to rearrangement. Rearrangement typically occurs when a more stable carbocation can form during the E1 mechanism. Look for secondary or tertiary carbocations that can rearrange to a more stable form (e.g., tertiary or resonance-stabilized carbocations).

Understand the E1 mechanism: The first step involves the loss of the leaving group to form a carbocation intermediate. Write the structure of the carbocation formed after the leaving group departs.

Check for possible carbocation rearrangements. This can include hydride shifts (movement of a hydrogen atom with its bonding electrons) or alkyl shifts (movement of an alkyl group with its bonding electrons) to form a more stable carbocation. Draw the rearranged carbocation if applicable.

Once the most stable carbocation is identified, proceed to the elimination step. A base will abstract a β-hydrogen (a hydrogen atom on a carbon adjacent to the carbocation), leading to the formation of a double bond. Identify all possible β-hydrogens and predict the major product based on Zaitsev's rule (the more substituted alkene is usually favored).

Draw the final product(s) of the reaction, ensuring that you account for any rearrangements and the regioselectivity of the elimination step. If multiple products are possible, indicate the major product based on stability and substitution patterns.

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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 is a type of elimination reaction that occurs in two steps: first, the formation of a carbocation intermediate after the leaving group departs, followed by the loss of a proton to form a double bond. This mechanism is favored in polar protic solvents and typically involves tertiary or stabilized carbocations, which can rearrange to more stable forms.

Carbocation Stability

Carbocation stability is crucial in predicting the outcome of E1 reactions. Carbocations are classified as primary, secondary, or tertiary based on the number of alkyl groups attached to the positively charged carbon. Tertiary carbocations are the most stable due to hyperconjugation and inductive effects, making them more likely to form during the reaction.

Rearrangement of Carbocations

Carbocation rearrangement occurs when a less stable carbocation transforms into a more stable one, often through hydride or alkyl shifts. This process is significant in E1 reactions, as the stability of the final product can be influenced by the rearrangement, leading to different alkene products based on the most stable carbocation formed during the reaction.

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