Table of contents

1. A Review of General Chemistry(0)
2. Molecular Representations(0)
3. Acids and Bases(0)
4. Alkanes and Cycloalkanes(0)
5. Chirality(0)
6. Thermodynamics and Kinetics(0)
7. Substitution Reactions(0)
8. Elimination Reactions(0)
9. Alkenes and Alkynes(0)
10. Addition Reactions(0)
11. Radical Reactions(0)
12. Alcohols, Ethers, Epoxides and Thiols(0)
13. Alcohols and Carbonyl Compounds(0)
14. Synthetic Techniques(0)
15. Analytical Techniques:IR, NMR, Mass Spect(0)
16. Conjugated Systems(0)
17. Ultraviolet Spectroscopy(0)
18. Aromaticity(0)
19. Reactions of Aromatics: EAS and Beyond(0)
20. Phenols(0)
21. Aldehydes and Ketones: Nucleophilic Addition(0)
22. Carboxylic Acid Derivatives: NAS(0)
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides(0)
24. Enolate Chemistry: Reactions at the Alpha-Carbon(0)
25. Condensation Chemistry(0)
26. Amines(0)
27. Heterocycles(0)
28. Carbohydrates(0)
29. Amino Acids(0)
30. Peptides and Proteins(0)
32. Lipids (0)
34. Nucleic Acids(0)
35. Transition Metals(0)

24. Enolate Chemistry: Reactions at the Alpha-Carbon

Enolate

24. Enolate Chemistry: Reactions at the Alpha-Carbon

Enolate - Online Tutor, Practice Problems & Exam Prep

Enolate Practice Problems

20 problems

The following two reactions show the alkylation of a ketoester under two different conditions. Draw the structures of A and B and indicate whether each of these products is formed under kinetic control or thermodynamic control.

2PRACTICE PROBLEM

Predict the product of the reaction given below.

3PRACTICE PROBLEM

Draw the deuterated product of the reaction given below.

4PRACTICE PROBLEM

Determine which of the following compounds would be fully deprotonated by a solution of sodium ethoxide in ethanol.

5PRACTICE PROBLEM

Draw the important resonance forms for the following ketone when the α-carbon atom of the ketone is deprotonated, giving an enolate ion.

(i) pentan-3-one

(ii) cyclohexanone

6PRACTICE PROBLEM

The aldol reaction is stereospecific and proceeds via the Zimmerman–Traxler transition state depicted below.

(a) Illustrate the arrow-pushing mechanism for step A and step B.

(b) Explain why this mechanism is favorable.

7PRACTICE PROBLEM

Draw the enolate(s) formed by the treatment of the following molecule with a base.

8PRACTICE PROBLEM

Draw the significant resonance structures of the enolate that result from the deprotonation of methyl 2-cyanobutanoate with a strong base.

9PRACTICE PROBLEM

Provide the significant resonance structures of the enolate that forms from the deprotonation of 1-cyclopentyl-2-nitroethanone with a strong base.

10PRACTICE PROBLEM

Given the following alkenone.

(i) Identify the most acidic hydrogens in the molecule.

(ii) When the most acidic hydrogen is removed, show structures of the significant resonance contributors of the resulting carbanion.

11PRACTICE PROBLEM

Given the following aldehyde below.

(i) Indicate the most acidic hydrogens in the molecule.

(ii) When the most acidic hydrogen is removed, draw the significant resonance contributors of the resulting carbanion.

12PRACTICE PROBLEM

Provide the significant resonance structures of the enolate that result from the deprotonation of dimethyl malonate.

13PRACTICE PROBLEM

Give the significant resonance structures of the possible enolate(s) that result from the deprotonation of the compound shown below.

14PRACTICE PROBLEM

Provide the significant resonance structures of the possible enolate(s) that result from the deprotonation of the compound shown below.

15PRACTICE PROBLEM

Draw the significant resonance structures of the possible enolate(s) that result from the deprotonation of the compound shown below.

16PRACTICE PROBLEM

Draw the resonance structures of the enolate ions produced by the deprotonation of the below-given compounds through a base.
a. cyclopentane-1,3-dione
b. methyl acetoacetate

17PRACTICE PROBLEM

A mixture of cis and trans isomers is obtained by dissolving trans-5-bromo-2-methylcyclohexanone in aqueous NaOH. Show the mechanism of this isomerization.

18PRACTICE PROBLEM

For the following compound: