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

24. Enolate Chemistry: Reactions at the Alpha-Carbon

Enolate

Organic Chemistry

24. Enolate Chemistry: Reactions at the Alpha-Carbon

Enolate

Previous problemNext problem

5:02 minutes

Problem 60h

Textbook Question

For each molecule shown below,
1. indicate the most acidic hydrogens.
2. draw the important resonance contributors of the anion that results from removal of the most acidic hydrogen.
(h)

Verified step by step guidance

Step 1: Identify the most acidic hydrogen in the molecule. The most acidic hydrogen is typically attached to an atom that can stabilize the resulting negative charge after deprotonation. Look for hydrogens attached to electronegative atoms (e.g., oxygen, nitrogen) or hydrogens in positions where the resulting anion can be stabilized by resonance or inductive effects.

Step 2: Analyze the structure of the molecule to determine if resonance stabilization is possible. If the negative charge formed after deprotonation can be delocalized through resonance, this increases the acidity of the hydrogen. Highlight the resonance-stabilizing groups or atoms in the molecule.

Step 3: Draw the resonance contributors for the anion formed after the removal of the most acidic hydrogen. Use curved arrows to show the movement of electrons that lead to each resonance structure. Ensure that all resonance structures follow the rules of resonance (e.g., maintaining the correct number of valence electrons and proper formal charges).

Step 4: Evaluate the stability of the resonance contributors. The more stable the resonance structures (e.g., those with full octets, minimal formal charges, and negative charges on more electronegative atoms), the more acidic the hydrogen is likely to be.

Step 5: Summarize the findings by clearly indicating the most acidic hydrogen(s) in the molecule and presenting the important resonance contributors of the resulting anion. Ensure that the resonance structures are drawn clearly and labeled appropriately.

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.

Acidity and Acidic Hydrogens

Acidity in organic chemistry refers to the tendency of a compound to donate a proton (H+). The most acidic hydrogens are typically those attached to electronegative atoms or in positions that stabilize the resulting anion through resonance or inductive effects. Identifying these hydrogens is crucial for predicting the behavior of the molecule in reactions.

Resonance Structures

Resonance structures are different ways of drawing a molecule that illustrate the delocalization of electrons. When a hydrogen is removed, the resulting anion can often be represented by multiple resonance contributors, which help to stabilize the negative charge. Understanding how to draw these structures is essential for predicting the stability and reactivity of the anion.

Anion Stability

The stability of an anion is influenced by factors such as charge distribution, electronegativity of atoms, and resonance. A more stable anion will be formed from the removal of the most acidic hydrogen, as it can better accommodate the negative charge. Analyzing the stability of the anion helps in understanding the overall acidity of the original molecule.

Watch next

Master Formation of Enolates with a bite sized video explanation from Johnny

Start learning