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

9. Alkenes and Alkynes

Dehydration Reaction

Organic Chemistry

9. Alkenes and Alkynes

Dehydration Reaction

Previous problemNext problem

4:58 minutes

Problem 44a

Textbook Question

Identify two different alcohols that can be dehydrated (one with rearrangement) to form the alkene shown.

Verified step by step guidance

Analyze the given alkene structure to determine its connectivity and identify possible positions for double bonds. This will help in deducing the alcohol precursors.

Recall that alcohol dehydration involves the loss of a water molecule, typically under acidic conditions, to form an alkene. The reaction follows either the E1 or E2 mechanism depending on the conditions.

For the first alcohol (without rearrangement), identify an alcohol structure where the hydroxyl group is directly attached to a carbon adjacent to the double bond in the alkene. This ensures direct elimination without rearrangement.

For the second alcohol (with rearrangement), consider a scenario where the initial carbocation formed during dehydration undergoes a hydride or alkyl shift to form a more stable carbocation. This rearranged carbocation then leads to the formation of the alkene.

Verify both alcohol structures by mentally performing the dehydration reaction and ensuring that the resulting alkene matches the given structure. Double-check for any stereochemical or regioselectivity considerations.

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.

Dehydration of Alcohols

Dehydration of alcohols is a chemical reaction where an alcohol loses a water molecule, typically resulting in the formation of an alkene. This process can occur through either an acid-catalyzed mechanism or via elimination reactions. Understanding the conditions and mechanisms of dehydration is crucial for predicting the products formed, especially when considering the stability of the resulting alkenes.

Carbocation Rearrangement

Carbocation rearrangement is a process where a carbocation (a positively charged carbon species) shifts to a more stable position during a reaction. This can involve hydride shifts or alkyl shifts, leading to the formation of more stable carbocations. Recognizing when and how rearrangements occur is essential for predicting the major products in dehydration reactions, particularly when multiple pathways are possible.

Alkene Stability and Zaitsev's Rule

Alkene stability is influenced by the degree of substitution on the double bond, with more substituted alkenes being more stable. Zaitsev's Rule states that during elimination reactions, the more substituted alkene is typically the major product. This principle helps in determining which alcohols to choose for dehydration, as it guides the prediction of the most stable alkene that can be formed from the starting materials.

Watch next

Master General features of acid-catalyzed dehydration. with a bite sized video explanation from Johnny

Start learning