Textbook Question
How could each of the following compounds be prepared from a ketone and an alkyl halide?
a.
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Ch. 17 - Reactions at the Alpha-Carbon
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
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Table of contents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 1)31
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 2)65
- Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry84
- Ch. 3 - An Introduction to Organic Compounds:Nomenclature, Physical Properties, and Structure183
- Ch. 4 - Isomers: The Arrangement of Atoms in Space121
- Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics83
- Ch. 6 - The Reactions of Alkenes • The Stereochemistry of Addition Reactions175
- Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis119
- Ch. 8 - Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene148
- Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides212
- Ch. 10 - Reactions of Alcohols, Ethers, Epoxides, Amines, and Sulfur-Containing Compounds131
- Ch. 11 - Organometallic Compounds60
- Ch. 12 - Radicals90
- Ch. 13 - Mass Spectrometry; Infrared Spectroscopy; UV/Vis Spectroscopy62
- Ch. 14 - NMR Spectroscopy95
- Ch. 15 - Reactions of Carboxylic Acids and Carboxylic Acid Derivatives123
- Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives141
- Ch. 17 - Reactions at the Alpha-Carbon101
- Ch. 18 - Reactions of Benzene and Substituted Benzenes144
- Ch. 19 - More About Amines • Reactions of Heterocyclic Compounds49
- Ch. 20 - The Organic Chemistry of Carbohydrates80
- Ch. 21 - Amino Acids, Peptides, and Proteins57
- Ch. 22 - Catalysis in Organic Reactions and in Enzymatic Reactions35
- Ch. 23 - The Organic Chemistry of the Coenzymes—Compounds Derived from Vitamins1
- Ch. 28 - Pericyclic Reactions58
Chapter 18, Problem 14b
How could each of the following compounds be prepared from a ketone and an alkyl halide?
b. 
Verified step by step guidance1
Step 1: Identify the target compound structure. The compound shown is a β-aryl ketone, which can be synthesized using a ketone and an alkyl halide through the alkylation of enolates.
Step 2: Select the ketone precursor. The ketone precursor should be cyclopentanone, as it provides the cyclic ketone structure in the target molecule.
Step 3: Select the alkyl halide. The alkyl halide should be benzyl bromide (C6H5CH2Br), as it introduces the benzyl group to the ketone.
Step 4: Generate the enolate. Treat cyclopentanone with a strong base, such as LDA (Lithium Diisopropylamide), to form the enolate ion. This step is crucial for nucleophilic attack on the alkyl halide.
Step 5: Perform the alkylation reaction. React the enolate ion with benzyl bromide in an SN2 reaction mechanism to form the β-aryl ketone shown in the target structure.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Enolate Formation
Enolates are formed from ketones through deprotonation at the alpha carbon, resulting in a resonance-stabilized anion. This process is typically facilitated by a strong base, which abstracts a proton, allowing the carbonyl compound to become nucleophilic. Enolates are crucial intermediates in various organic reactions, including alkylation and acylation.
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Formation of Enolates
Alkylation of Enolates
Alkylation involves the reaction of an enolate ion with an alkyl halide, where the nucleophilic enolate attacks the electrophilic carbon of the halide. This reaction results in the formation of a new carbon-carbon bond, extending the carbon chain. The choice of alkyl halide can influence the regioselectivity and stereochemistry of the product formed.
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Acylation of Enolates
Acylation of enolates involves the reaction of an enolate with an acyl halide or an acid anhydride, leading to the formation of a β-keto ester or a β-diketone. This process allows for the introduction of acyl groups into the molecule, which can further participate in various synthetic transformations. Acylation is a key step in the synthesis of complex organic molecules.
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Related Practice
Textbook Question
How could each of the following compounds be prepared from cyclohexanone?
a.
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Textbook Question
Show how the following compounds can be prepared from the given starting material:
a.
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Textbook Question
A ketone undergoes acid-catalyzed bromination, acid-catalyzed chlorination, racemization, and acid-catalyzed deuterium exchange at the ⍺-carbon. All of these reactions have similar rate constants.What does this tell you about the mechanisms of these reactions?
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Textbook Question
How could each of the following compounds be prepared from cyclohexanone?
b.
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Textbook Question
Describe how the following compounds could be prepared from cyclohexanone using an enamine intermediate:
a.
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