Textbook Question
Give the important resonance forms for the possible enolate ions of the following:
(d)
668
views
Ch. 22 - Condensations and Alpha Substitutions of Carbonyl Compounds
Wade9th EditionOrganic ChemistryISBN: 9780135213728
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 - Structure and Bonding107
- Ch. 2 - Acids and Bases; Functional Groups115
- Ch.3 - Structure and Stereochemistry of Alkanes100
- Ch.4 - The Study of Chemical Reactions99
- Ch.5 - Stereochemistry93
- Ch.6 - Alkyl Halides; Nucleophilic Substitution118
- Ch. 7 - Structure and Synthesis of Alkenes; Elimination158
- Ch.8 - Reactions of Alkenes171
- Ch.9 - Alkynes91
- Ch.10 - Structure and Synthesis of Alcohols143
- Ch.11 - Reactions of Alcohols104
- Ch. 12 - Infrared Spectroscopy and Mass Spectrometry22
- Ch. 13 - Nuclear Magnetic Resonance Spectroscopy45
- Ch. 14 - Ethers, Epoxides, and Thioethers72
- Ch. 15 - Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy89
- Ch. 16 - Aromatic Compounds74
- Ch. 17 - Reactions of Aromatic Compounds126
- Ch. 18 - Ketones and Aldehydes193
- Ch. 19 - Amines129
- Ch. 20 - Carboxylic Acids77
- Ch. 21 - Carboxylic Acid Derivatives141
- Ch. 22 - Condensations and Alpha Substitutions of Carbonyl Compounds175
- Ch. 23 - Carbohydrates and Nucleic Acids93
- Ch. 24 - Amino Acids, Peptides, and Proteins54
All textbooks
Wade 9th EditionCh. 22 - Condensations and Alpha Substitutions of Carbonyl CompoundsProblem 3a,b
Wade 9th EditionCh. 22 - Condensations and Alpha Substitutions of Carbonyl CompoundsProblem 3a,bChapter 22, Problem 3a,b
Give the important resonance forms for the possible enolate ions of the following:
(a) acetone
(b) cyclopentanone
Verified step by step guidance1
Step 1: Understand the concept of enolate ions. Enolate ions are formed when a proton is removed from the alpha-carbon (the carbon adjacent to the carbonyl group) of a ketone or aldehyde. This results in a resonance-stabilized anion where the negative charge is delocalized between the oxygen atom and the alpha-carbon.
Step 2: For acetone (CH₃COCH₃), identify the alpha-hydrogens. Acetone has two methyl groups attached to the carbonyl carbon, and each methyl group has three alpha-hydrogens. Deprotonation of one of these alpha-hydrogens leads to the formation of the enolate ion.
Step 3: Draw the enolate ion for acetone. After deprotonation, the negative charge is initially on the alpha-carbon. Use resonance to delocalize the negative charge to the oxygen atom of the carbonyl group. Write the two resonance forms: one with the negative charge on the alpha-carbon and one with the negative charge on the oxygen atom.
Step 4: For cyclopentanone, identify the alpha-hydrogens. Cyclopentanone has two alpha-carbons (on either side of the carbonyl group), each with two alpha-hydrogens. Deprotonation of one of these alpha-hydrogens leads to the formation of the enolate ion.
Step 5: Draw the enolate ion for cyclopentanone. Similar to acetone, the negative charge is initially on the alpha-carbon after deprotonation. Use resonance to delocalize the negative charge to the oxygen atom of the carbonyl group. Write the two resonance forms: one with the negative charge on the alpha-carbon and one with the negative charge on the oxygen atom.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Enolate Ions
Enolate ions are reactive intermediates formed from the deprotonation of carbonyl compounds, such as ketones and aldehydes. They contain a negatively charged carbon atom adjacent to a carbonyl group, which allows for resonance stabilization. Understanding the formation and stability of enolate ions is crucial for predicting their reactivity in organic reactions, particularly in nucleophilic addition and alkylation processes.
Recommended video:
Guided course
02:26
Formation of Enolates
Resonance Structures
Resonance structures are different Lewis structures for the same molecule that illustrate the delocalization of electrons. In the case of enolate ions, resonance forms help visualize how the negative charge can be distributed between the carbon atom and the oxygen atom of the carbonyl group. This delocalization contributes to the stability of the enolate ion, making it a key concept in understanding its reactivity and behavior in organic reactions.
Recommended video:
Guided course
03:04Drawing Resonance Structures
Carbonyl Compounds
Carbonyl compounds, which include aldehydes and ketones, are characterized by the presence of a carbonyl group (C=O). The reactivity of these compounds is significantly influenced by the nature of the carbonyl group, which can undergo various transformations, including enolate formation. Recognizing the structure and properties of carbonyl compounds is essential for predicting the formation of enolates and their subsequent reactions in organic synthesis.
Recommended video:
Guided course
01:40Defining meso compounds.
Related Practice
Textbook Question
Give the important resonance forms for the possible enolate ions of the following:
(e)
623
views
Textbook Question
Show each step in the mechanism of the acid-catalyzed interconversion of (R)- and (S)-3-methylpentan-2-one.
1492
views
Textbook Question
When cis-2,4-dimethylcyclohexanone is dissolved in aqueous ethanol containing a trace of NaOH, a mixture of cis and trans isomers results. Propose a mechanism for this isomerization.
1298
views
Textbook Question
Give the important resonance forms for the possible enolate ions of the following:
(c) pentane-2,4-dione
600
views
Textbook Question
Phenylacetone can form two different enols.
(c) Propose mechanisms for the formation of the first enol in acid.
887
views