Textbook Question
Predict the product of the following [2 + 2] cycloadditions.
(a)
Ch. 22 - Conjugated Systems II: Pericyclic Reactions
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
Chapter 21, Problem 30a
Predict the product of the following electrocyclic reactions.
(a) 
Verified step by step guidance1
Identify the type of electrocyclic reaction: The given reaction involves a cyclic compound with conjugated double bonds, indicating a potential electrocyclic reaction.
Determine the number of π-electrons involved: Count the π-electrons in the conjugated system. In this case, there are 6 π-electrons.
Apply the Woodward-Hoffmann rules: For a thermal reaction with 4n+2 π-electrons (where n is an integer), the reaction proceeds via a conrotatory mechanism.
Visualize the conrotatory mechanism: In a conrotatory process, the ends of the π-system rotate in the same direction (either both clockwise or both counterclockwise) to form a new σ-bond.
Predict the stereochemistry of the product: The conrotatory closure will result in a specific stereochemistry for the newly formed ring, which should be drawn to reflect the correct 3D orientation of substituents.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Electrocyclic Reactions
Electrocyclic reactions are a type of pericyclic reaction where a conjugated pi-electron system undergoes a ring closure or opening. These reactions are characterized by the conversion of pi bonds to sigma bonds or vice versa, and they are influenced by the number of pi electrons and the reaction conditions, such as heat or light.
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08:11
Predicting Electrocyclic Products
Woodward-Hoffmann Rules
The Woodward-Hoffmann rules predict the stereochemistry of pericyclic reactions, including electrocyclic reactions, based on the conservation of orbital symmetry. For thermal reactions, these rules state that systems with 4n pi electrons undergo conrotatory closure, while those with 4n+2 pi electrons undergo disrotatory closure, determining the stereochemical outcome of the reaction.
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1:18Woodward-Fieser Rules Example 1
Conrotatory and Disrotatory Motion
In electrocyclic reactions, conrotatory motion involves the rotation of terminal groups in the same direction, while disrotatory motion involves rotation in opposite directions. The type of motion affects the stereochemistry of the product, with conrotatory leading to cis products and disrotatory leading to trans products, depending on the number of pi electrons and reaction conditions.
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05:51Two Steps to Predicting Any Electrocyclic Products
Related Practice
Textbook Question
Predict the product of the following [2 + 2] cycloadditions.
(b)
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Textbook Question
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(b)
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(c)
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