Textbook Question
Draw the product of each of the following reactions:
2.
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Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides
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. 9 - Substitution and Elimination Reactions of Alkyl HalidesProblem 120a(1)
Bruice 8th EditionCh. 9 - Substitution and Elimination Reactions of Alkyl HalidesProblem 120a(1)Chapter 10, Problem 120a(1)
Draw the product of each of the following reactions:
1. 
Verified step by step guidance1
Step 1: Analyze the given reactants and reagents. The starting material is CH3CH2C≡CH (1-butyne), and the reaction involves two steps: (1) NaNH2 (sodium amide) and (2) CH3CH2Br (ethyl bromide). Sodium amide is a strong base that can deprotonate terminal alkynes, generating an acetylide ion.
Step 2: In the first step, NaNH2 deprotonates the terminal alkyne (CH3CH2C≡CH) to form the corresponding acetylide ion (CH3CH2C≡C⁻). This occurs because the terminal hydrogen on the alkyne is acidic and can be removed by a strong base.
Step 3: In the second step, the acetylide ion (CH3CH2C≡C⁻) acts as a nucleophile and undergoes an SN2 reaction with CH3CH2Br (ethyl bromide). The bromine atom in CH3CH2Br is a good leaving group, allowing the nucleophilic substitution to occur.
Step 4: The nucleophilic attack by the acetylide ion on the ethyl bromide results in the formation of a new carbon-carbon bond. The product of this reaction is an internal alkyne, specifically CH3CH2C≡CCH2CH3.
Step 5: Verify the structure of the product by ensuring that the reaction mechanism is consistent with the reagents used (deprotonation followed by nucleophilic substitution) and that the final product is an internal alkyne with the correct connectivity.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Alkyne Reactivity
Alkynes are hydrocarbons containing a carbon-carbon triple bond, which makes them highly reactive. In organic reactions, they can undergo various transformations, including nucleophilic substitutions and eliminations. Understanding the reactivity of alkynes is crucial for predicting the products of reactions involving them.
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Alkyne Hydration
Nucleophilic Substitution
Nucleophilic substitution is a fundamental reaction mechanism in organic chemistry where a nucleophile replaces a leaving group in a molecule. In this case, sodium amide (NaNH2) acts as a strong nucleophile, facilitating the substitution of a hydrogen atom in the alkyne with a bromine atom from bromoethane (CH3CH2Br). This concept is essential for determining the final product of the reaction.
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Reaction Mechanism
A reaction mechanism describes the step-by-step process by which reactants are converted into products. It includes the identification of intermediates, transition states, and the overall energy changes. Understanding the mechanism of the reaction between the alkyne and sodium amide is vital for predicting the structure of the final product and the pathway taken during the reaction.
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Related Practice
Textbook Question
Give two sets of reactants (each set including an alkyl halide and a nucleophile) that could be used to synthesize the following ether:
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Textbook Question
cis-4-Bromocyclohexanol and trans-4-bromocyclohexanol form the same elimination product but a different substitution product when they react with HO−.
a. Why do they form the same elimination product?
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Textbook Question
cis-4-Bromocyclohexanol and trans-4-bromocyclohexanol form the same elimination product but a different substitution product when they react with HO−.
b. Explain, by showing the mechanisms, why different substitution products are obtained.
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Textbook Question
Give two sets of reactants (each set including an alkyl halide and a nucleophile) that could be used to synthesize the following alkyne:
CH3CH2C≡CCH2CH2CH2CH3
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Textbook Question
cis-4-Bromocyclohexanol and trans-4-bromocyclohexanol form the same elimination product but a different substitution product when they react with HO−.
c. How many stereoisomers does each of the elimination and substitution reactions form?
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