Textbook Question
What alkyl bromide should be used in the acetoacetic ester synthesis of each of the following methyl ketones? b. 2-octanone
931
views
Ch. 17 - Reactions at the Alpha-Carbon
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
Not the one you use?Change textbookSelect a different textbook
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 41c
What alkyl bromide should be used in the acetoacetic ester synthesis of each of the following methyl ketones? c. 4-phenyl-2-butanone
Verified step by step guidance1
Identify the target methyl ketone: The target compound is 4-phenyl-2-butanone, which has the structure C6H5-CH2-CH2-CO-CH3. This is a methyl ketone with a phenyl group attached to the fourth carbon.
Recall the acetoacetic ester synthesis: This reaction involves the alkylation of ethyl acetoacetate (CH3COCH2COOEt) followed by hydrolysis and decarboxylation to yield a methyl ketone. The key step is selecting the appropriate alkyl bromide for the alkylation step.
Analyze the structure of the target compound: The target compound has a phenyl group (C6H5-) and a two-carbon chain (CH2-CH2-) leading to the ketone group. This suggests that the alkyl bromide should introduce the phenyl-ethyl group (C6H5-CH2-CH2-).
Determine the alkyl bromide: To introduce the phenyl-ethyl group, the appropriate alkyl bromide is phenylethyl bromide (C6H5-CH2-CH2-Br). This will react with the enolate of ethyl acetoacetate during the alkylation step.
Summarize the reaction: The enolate of ethyl acetoacetate reacts with phenylethyl bromide in the presence of a base (e.g., NaOEt) to form the alkylated product. Subsequent hydrolysis and decarboxylation yield the desired methyl ketone, 4-phenyl-2-butanone.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Acetoacetic Ester Synthesis
Acetoacetic ester synthesis is a method for forming ketones from acetoacetic ester and an alkyl halide. This reaction involves the nucleophilic substitution of the ester enolate with an alkyl halide, leading to the formation of a β-keto ester. Understanding this process is crucial for determining the appropriate alkyl bromide to use in synthesizing specific ketones.
Recommended video:
01:28
Synthesis of Amino Acids: Acetamidomalonic Ester Synthesis Example 2
Enolate Formation
Enolate formation is a key step in acetoacetic ester synthesis, where a base abstracts a proton from the α-carbon of the acetoacetic ester, generating a resonance-stabilized enolate ion. This enolate acts as a nucleophile, allowing it to react with an alkyl halide. Recognizing how to form and stabilize enolates is essential for predicting the outcome of the synthesis.
Recommended video:
Guided course
02:26Formation of Enolates
Alkyl Halide Selection
The selection of the appropriate alkyl halide is critical in acetoacetic ester synthesis, as it determines the structure of the final ketone product. The alkyl halide must be compatible with the enolate formed from the acetoacetic ester, typically being a primary or secondary halide to minimize steric hindrance. Understanding the reactivity and structure of alkyl halides is vital for successful synthesis.
Recommended video:
Guided course
01:52How to name alkyl halides
Related Practice
Textbook Question
Draw a structure for each of the following:
a. ethyl acetoacetate
1387
views
Textbook Question
Design a synthesis for each of the following compounds using the given starting material:
b.
57
views
Textbook Question
Design a synthesis for each of the following compounds using the given starting material:
d.
68
views
Textbook Question
What alkyl bromide should be used in the acetoacetic ester synthesis of each of the following methyl ketones? a. 2-pentanone
1020
views
Textbook Question
Explain why the following carboxylic acids cannot be prepared by a malonic ester synthesis:
c.
1203
views