Textbook Question
Show a reaction coordinate diagram for the two processes in Figure 13.41 that rationalizes pathway B as the one that gives the major product.
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Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471
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Table of contents
- Ch. 2 - General Chemistry Translated: Finding the Electrons114
- Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis109
- Ch. 4 - Acids and Bases: Electron Flow144
- Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics118
- Ch. 6 - Stereoisomerism: Arrangement of Atoms in Space112
- Ch. 7 - Principles of Green (Organic) Chemistry3
- Ch. 8 - Alkenes I: Properties and Electrophilic Additions158
- Ch. 9 - Alkenes II: Oxidation and Reduction150
- Ch. 10 - Alkynes: Electrophilic Addition and Redox Reactions101
- Ch. 11 - Properties and Synthesis of Alkyl Halides: Radical Reactions108
- Ch. 12 - Substitution and Elimination: Reactions of Haloalkanes172
- Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination239
- Ch. 14 - Structural Identification I: Infrared Spectroscopy and Mass Spectrometry54
- Ch. 15 - Structural Identification II: Nuclear Magnetic Resonance Spectroscopy93
- Ch. 16 - Metals in Organic Chemistry48
- Ch. 17 - Carbonyl Addition Reactions: Aldehydes and Ketones45
- Ch. 18 - Nucleophilic Acyl Substitution I: Carboxylic Acids18
- Ch. 19 - Nucleophilic Acyl Substitution II: Carboxylic Acid Derivatives39
- Ch. 20 - Enolates: Carbonyl Addition and Substitution13
- Ch. 21 - Conjugated Systems I: Stability and Addition Reactions56
- Ch. 22 - Conjugated Systems II: Pericyclic Reactions54
- Ch. 23 - Benzene I: Aromatic Stability and Substitution Reactions64
- Ch. 24 - Benzene II: Reactions Influenced by the Aromatic Ring62
- Ch. 25 - Amines: Structure, Reactions, and Synthesis27
- Ch. 26 - Amino Acids, Proteins, and Peptide Synthesis9
- Ch. 27 - Carbohydrates, Nucleic Acids, and Lipids54
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
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Mullins 1st EditionCh. 13 - Alcohols, Ethers and Related Compounds: Substitution and EliminationProblem 47c
Mullins 1st EditionCh. 13 - Alcohols, Ethers and Related Compounds: Substitution and EliminationProblem 47cChapter 12, Problem 47c
Suggest an alkene that, in two steps, could be converted into each of the following ketones. Each sequence should involve a pinacol rearrangement.
(c) 
Verified step by step guidance1
Step 1: Identify the target ketone structure. The ketone shown has a carbonyl group on the terminal carbon of a chain, with a branched alkyl group attached to the second carbon. This suggests that the precursor molecule must have a hydroxyl group on the carbon adjacent to the carbonyl group after rearrangement.
Step 2: Recall the pinacol rearrangement mechanism. This reaction involves a vicinal diol (two hydroxyl groups on adjacent carbons) undergoing acid-catalyzed rearrangement to form a ketone. Therefore, the intermediate before the rearrangement must be a vicinal diol.
Step 3: Determine the alkene that can lead to the vicinal diol. Alkenes can be converted into vicinal diols via hydroxylation reactions, such as using osmium tetroxide (OsO₄) or potassium permanganate (KMnO₄). The alkene should have the correct substitution pattern to yield the desired diol.
Step 4: Propose the alkene structure. The alkene should have a double bond between the second and third carbons of the chain, with a methyl group attached to the second carbon. This substitution pattern ensures that hydroxylation will produce the correct vicinal diol.
Step 5: Outline the two-step process. First, perform hydroxylation of the alkene to produce the vicinal diol. Second, subject the vicinal diol to acid-catalyzed pinacol rearrangement to yield the target ketone.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Alkene Reactivity
Alkenes are hydrocarbons that contain a carbon-carbon double bond, making them reactive intermediates in organic reactions. Their reactivity is primarily due to the presence of the π bond, which can participate in various reactions such as electrophilic addition, oxidation, and rearrangement. Understanding the types of reactions that alkenes can undergo is crucial for designing synthetic pathways to target compounds.
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Alkene Metathesis Concept 1
Pinacol Rearrangement
The pinacol rearrangement is a chemical reaction that involves the conversion of a pinacol (a 1,2-diol) into a ketone or aldehyde through a rearrangement process. This reaction typically occurs under acidic conditions and involves the migration of an alkyl group and the formation of a carbocation intermediate. Recognizing how this rearrangement alters the structure of the starting material is essential for predicting the final product in synthetic routes.
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Synthetic Strategy
A synthetic strategy in organic chemistry refers to the planned sequence of reactions and transformations used to construct a target molecule from simpler starting materials. This involves selecting appropriate reagents, reaction conditions, and intermediates to achieve the desired product efficiently. In the context of the question, devising a two-step synthesis involving an alkene and a pinacol rearrangement requires careful consideration of the starting materials and the desired ketone structure.
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Related Practice
Textbook Question
The intermediates for the Swern oxidation, a reaction introduced in Section 13.9.4, are shown. Provide the arrow-pushing mechanism that rationalizes the formation of each intermediate and the final product(s).
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Textbook Question
Predict the product of the following pinacol rearrangements.
(c)
Textbook Question
In Assessment 13.48, identify the individual step that represents the general mechanism for all alcohol oxidation reactions.
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Textbook Question
Every oxidation is accompanied by a reduction. Identify the species that is reduced in the Swern oxidation in Assessment 13.48.
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Textbook Question
Predict the product of the following pinacol rearrangements.
(b)
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