Textbook Question
Draw the products of the following reactions:
c.
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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 71b
b. What carboxylic acid is formed when the malonic ester synthesis is carried out with two equivalents of malonic ester, one equivalent of 1,5-dibromopentane, and two equivalents of base?
Verified step by step guidance1
Step 1: Begin by understanding the malonic ester synthesis. This reaction involves the alkylation of malonic ester (diethyl malonate) using a base and an alkyl halide, followed by hydrolysis and decarboxylation to yield a carboxylic acid.
Step 2: In this case, two equivalents of malonic ester are used along with one equivalent of 1,5-dibromopentane and two equivalents of base (CH3CH2ONa). The base deprotonates the alpha-hydrogens of the malonic ester, making it nucleophilic.
Step 3: The nucleophilic malonic ester attacks the 1,5-dibromopentane, displacing one bromide ion and forming a bond between the malonic ester and the pentane chain. This step occurs twice due to the two equivalents of malonic ester, resulting in a molecule with two malonic ester groups attached to the pentane chain.
Step 4: The reaction mixture is then subjected to acidic hydrolysis (HCl, H2O), which converts the ester groups into carboxylic acids. This step yields a compound with two carboxylic acid groups attached to the pentane chain.
Step 5: Finally, decarboxylation occurs under heating (Δ), removing one of the carboxylic acid groups from each malonic acid moiety. The final product is a carboxylic acid with a single carboxylic acid group at each end of the pentane chain, resulting in 1,5-pentanedioic acid (glutaric acid).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Malonic Ester Synthesis
Malonic ester synthesis is a method for synthesizing carboxylic acids through the alkylation of malonic ester. In this reaction, a malonic ester is treated with a base to deprotonate one of its acidic protons, allowing it to act as a nucleophile. The nucleophilic malonic ester then reacts with an alkyl halide, such as 1,5-dibromopentane, leading to the formation of a substituted malonic ester, which can subsequently be hydrolyzed and decarboxylated to yield the final carboxylic acid product.
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Carboxylic Acids
Carboxylic acids are organic compounds characterized by the presence of one or more carboxyl groups (-COOH). They are known for their acidic properties due to the ability of the carboxyl group to donate a proton (H+). In the context of malonic ester synthesis, the final product is a carboxylic acid that results from the hydrolysis and decarboxylation of the intermediate malonic ester, which is crucial for understanding the outcome of the reaction.
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Base-Induced Reactions
In organic chemistry, bases are often used to deprotonate acidic protons, facilitating nucleophilic attacks in various reactions. In the malonic ester synthesis, a strong base such as sodium ethoxide is employed to deprotonate the malonic ester, generating a nucleophile that can react with the alkyl halide. Understanding the role of the base is essential for predicting the reaction pathway and the formation of the desired carboxylic acid product.
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Related Practice
Textbook Question
Indicate how the following compounds can be synthesized from cyclohexanone and any other necessary reagents:
d.
1029
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Textbook Question
The ketone whose 1H NMR spectrum is shown here was obtained as the product of an acetoacetic ester synthesis. What alkyl halide was used in the synthesis?
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1637
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Textbook Question
Draw the products of the following reactions:
b.
999
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Textbook Question
Compound A with molecular formula C6H10 has two peaks in its 1H NMR spectrum, both of which are singlets (with ratio 9 : 1). Compound A reacts with an acidic aqueous solution containing mercuric sulfate to form compound B, which gives a positive iodoform test (Problem 58) and has an 1H NMR spectrum that shows two singlets (with ratio 3 : 1). Identify A and B.
1624
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Textbook Question
Draw the products of the following reactions:
a.
1099
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