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 72a
Draw the products of the following reactions:
a. 
Verified step by step guidance1
Step 1: Analyze the structure of the starting compound. The molecule contains two ester groups separated by a methylene chain. Each ester group has a carbonyl carbon attached to an oxygen atom and a methyl group.
Step 2: Consider the first reagent, CH3O⁻ (methoxide ion). Methoxide is a strong nucleophile and base. It will likely initiate a nucleophilic attack or deprotonation. In this case, it will deprotonate the alpha-hydrogen (hydrogen on the carbon adjacent to the carbonyl group) of one of the esters, forming an enolate ion.
Step 3: The enolate ion formed is a resonance-stabilized intermediate. The negative charge on the alpha-carbon can attack the carbonyl carbon of the second ester group, leading to an intramolecular reaction. This step forms a cyclic intermediate.
Step 4: After the intramolecular attack, the cyclic intermediate undergoes protonation when HCl is added in the second step. HCl provides protons to stabilize the intermediate and complete the reaction.
Step 5: The final product is a cyclic β-keto ester. The reaction results in the formation of a ring structure due to the intramolecular attack, and the ester group remains intact in the product.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Claisen Condensation
Claisen condensation is a reaction between two esters or an ester and a carbonyl compound in the presence of a strong base, leading to the formation of a β-keto ester or a β-diketone. This reaction involves the nucleophilic attack of an enolate ion on the carbonyl carbon of another ester, followed by the elimination of an alcohol. Understanding this mechanism is crucial for predicting the products of the reaction shown.
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08:28
Claisen Condensation
Enolate Ion Formation
Enolate ions are formed when a base abstracts a proton from the α-carbon of a carbonyl compound, resulting in a resonance-stabilized anion. This species is a key intermediate in many organic reactions, including the Claisen condensation. The stability and reactivity of the enolate ion determine the course of the reaction, making it essential to grasp how to generate and utilize these intermediates effectively.
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02:26Formation of Enolates
Acid-Base Reactions
Acid-base reactions involve the transfer of protons (H+) between reactants, which can influence the outcome of organic reactions. In the context of the given reaction, HCl serves as an acid that can protonate the enolate ion or other intermediates, stabilizing them or facilitating further reactions. Understanding the role of acids and bases is vital for predicting product formation and reaction pathways in organic chemistry.
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02:49The Lewis definition of acids and bases.
Related Practice
Textbook Question
Indicate how the following compounds can be synthesized from cyclohexanone and any other necessary reagents:
d.
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Textbook Question
Draw the products of the following reactions:
b.
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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.
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Textbook Question
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?
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Textbook Question
Draw the products of the following reactions:
d.
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