Textbook Question
What is the major elimination product obtained from an E2 reaction of each of the following alkyl halides with hydroxide ion?
f.
1511
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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 23c,d
Bruice 8th EditionCh. 9 - Substitution and Elimination Reactions of Alkyl HalidesProblem 23c,dChapter 10, Problem 23c,d
What is the major elimination product obtained from an E2 reaction of each of the following alkyl halides with hydroxide ion?
c. 
d. 
Verified step by step guidance1
Step 1: Analyze the structure of the alkyl halide provided in each case. For the first structure (c), the molecule is 3-chloro-4-pentene, and for the second structure (d), the molecule is 2-fluoropentane. Identify the halogen atom and its position on the carbon chain.
Step 2: Recall the mechanism of the E2 elimination reaction. In an E2 reaction, a strong base (hydroxide ion in this case) abstracts a proton from a β-carbon (a carbon adjacent to the carbon bonded to the halogen), while the halogen leaves as a leaving group. This results in the formation of a double bond.
Step 3: For structure (c), identify the β-hydrogens available for elimination. The β-carbons are the carbons adjacent to the carbon bonded to chlorine. Consider the regioselectivity of the elimination reaction (Zaitsev's rule), which states that the more substituted alkene is generally the major product.
Step 4: For structure (d), identify the β-hydrogens available for elimination. The β-carbons are the carbons adjacent to the carbon bonded to fluorine. Apply Zaitsev's rule to determine the major product, keeping in mind that fluorine is a poor leaving group, which may influence the reaction.
Step 5: Draw the possible elimination products for each structure and determine the major product based on the stability of the alkenes formed. For structure (c), the double bond will likely form between the β-carbon and the α-carbon (carbon bonded to chlorine). For structure (d), the double bond will likely form between the β-carbon and the α-carbon (carbon bonded to fluorine).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
E2 Reaction Mechanism
The E2 (bimolecular elimination) reaction is a concerted mechanism where a base abstracts a proton from a β-carbon while a leaving group departs from the α-carbon, resulting in the formation of a double bond. This reaction typically requires strong bases and is characterized by a single transition state, leading to the formation of alkenes.
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Drawing the E2 Mechanism.
Zaitsev's Rule
Zaitsev's Rule states that in elimination reactions, the more substituted alkene is generally the major product. This occurs because more substituted alkenes are more stable due to hyperconjugation and the inductive effect, making them thermodynamically favored over less substituted counterparts.
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Sterics and Regioselectivity
Sterics refers to the spatial arrangement of atoms in a molecule, which can influence the outcome of reactions. In E2 reactions, steric hindrance can affect which β-hydrogen is abstracted, leading to regioselectivity in the formation of the alkene product. Bulky bases may favor less hindered pathways, impacting the major product formed.
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Related Practice
Textbook Question
What is the major elimination product obtained from the reaction of each of the following alkyl halides with hydroxide ion?
c.
1572
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Textbook Question
What is the major elimination product obtained from an E2 reaction of each of the following alkyl halides with hydroxide ion?
b.
1122
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Textbook Question
Which alkyl halide in each pair is more reactive in an E2 reaction with hydroxide ion?
a.
b.
804
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Textbook Question
What is the major elimination product obtained from an E2 reaction of each of the following alkyl halides with hydroxide ion?
e.
1483
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Textbook Question
What is the major elimination product obtained from an E2 reaction of each of the following alkyl halides with hydroxide ion?
a.
1269
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