Textbook Question
Draw structures for A-D for each of the following:
b.
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Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives
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
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Bruice 8th EditionCh. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid DerivativesProblem 78a
Bruice 8th EditionCh. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid DerivativesProblem 78aChapter 17, Problem 78a
Propose a mechanism for each of the following reactions:
a. 
Verified step by step guidance1
Step 1: Analyze the reactants and reagents. The starting material is a molecule containing two ketone groups and an ester functional group. The reagent CH3MgBr is a Grignard reagent, which acts as a nucleophile, and H3O+ is used for acidic workup.
Step 2: Identify the site of nucleophilic attack. The Grignard reagent (CH3MgBr) will attack the carbonyl carbon of the ester group because esters are more reactive towards nucleophiles compared to ketones.
Step 3: Describe the nucleophilic addition. The CH3 group from CH3MgBr will add to the carbonyl carbon of the ester, breaking the C=O bond and forming a tetrahedral intermediate. The ethoxy group (-OCH2CH3) will leave as a leaving group, resulting in a ketone intermediate.
Step 4: Explain the second nucleophilic attack. The Grignard reagent will attack the newly formed ketone group, adding another CH3 group to the carbonyl carbon and forming a tertiary alcohol intermediate.
Step 5: Describe the acidic workup. The H3O+ will protonate the oxygen atoms, stabilizing the molecule and leading to the formation of the final cyclic ketone product and ethanol (CH3CH2OH) as a byproduct.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Grignard Reagents
Grignard reagents are organomagnesium compounds, typically represented as R-MgX, where R is an organic group and X is a halogen. They are highly reactive nucleophiles that can add to electrophilic carbonyl groups, such as aldehydes and ketones, forming alcohols after hydrolysis. Understanding their reactivity is crucial for proposing mechanisms involving carbonyl compounds.
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Carbonation of Grignard Reagents
Nucleophilic Addition Mechanism
The nucleophilic addition mechanism involves the attack of a nucleophile on an electrophilic carbon atom, leading to the formation of a new bond. In the case of Grignard reagents reacting with carbonyl compounds, the nucleophile (Grignard reagent) attacks the carbonyl carbon, resulting in a tetrahedral intermediate. This step is fundamental in understanding how carbonyl compounds are converted into alcohols.
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08:27Nucleophilic Addition
Protonation of Alkoxide
After the nucleophilic addition, the reaction typically involves protonation of the alkoxide intermediate formed. This step is crucial as it converts the alkoxide into a stable alcohol. In the provided reaction, the addition of water (H3O+) serves to protonate the alkoxide, completing the transformation of the carbonyl compound into an alcohol, which is a key outcome of the reaction.
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Related Practice
Textbook Question
Propose a mechanism to explain how dimethyl sulfoxide and oxalyl chloride react to form the dimethylchlorosulfonium ion used as the oxidizing agent in the Swern oxidation.
Textbook Question
What product is formed when 3-methyl-2-cyclohexenone reacts with each of the following reagents?
c. HBr
d. CH3CH2SH
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Textbook Question
Propose a mechanism for each of the following reactions:
b.
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Textbook Question
What product is formed when 3-methyl-2-cyclohexenone reacts with each of the following reagents?
a. CH3MgBr followed by H3O+
b. (CH3CH2)2CuLi followed by H3O+
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Textbook Question
What is the product of each of the following reactions?
c.
d.
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