Concept explainers
(a)
Interpretation:
The following pericyclic reaction is to be classified. (More than one classification is possible.)
Concept introduction:
Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. In some cases, Lewis acid catalysts can also be applied. Though, the position of π-bond is changed in Sigmatropic reaction, the total number of π-bonds remain unchanged. The sigma bond can be cleaved at the middle or at the end of the π-system. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement.
(b)
Interpretation:
Suppose the migrating methyl group in part (a) were labeled with the hydrogen isotopes deuterium (D) and tritium (T) so that it is a -CHDT group with the S configuration. The configuration of this group in the product is to be stated.
Concept introduction:
Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. In some cases, Lewis acid catalysts can also be applied. Though, the position of π-bond is changed in Sigmatropic reaction, the total number of π-bonds remain unchanged. The sigma bond can be cleaved at the middle or at the end of the π-system.
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 28 Solutions
EBK ORGANIC CHEMISTRY STUDY GUIDE AND S
- Resveratrol is an antioxidant found in the skin of red grapes. Its anticancer, anti-inflammatory, and various cardiovascular effects are under active investigation. (a) Draw all resonance structures for the radical that results from homolysis of the OH bond shown in red. (b) Explain why homolysis of this OH bond is preferred to homolysis of either OH bond in the other benzene ring.arrow_forward(a) Why are alkyl halides insoluble in water? (b) Why is Butan-l-ol optically inactive but Butan-2-ol is optically active? (c) Although chlorine is an electron withdrawing group, yet it is ortho-, Para- directing in electrophilic aromatic substitution reaction. Why?arrow_forward(a) What functional group is undergoing a transformation in the reaction? (b) What functional group is it being transformed into (in the final product)?arrow_forward
- Resveratrol is an antioxidant found in the skin of red grapes. Its anticancer, anti-inammatory, and various cardiovascular effects are under active investigation. (a) Draw all resonance structures for the radical that results from homolysis of the OH bond shown in red. (b) Explain why homolysis of this OH bond is preferred to homolysis of either OH bond in the other benzene ring.arrow_forward(a) One test for the presence of an alkene is to add a smallamount of bromine, which is a red-brown liquid, and lookfor the disappearance of the red-brown color. This test doesnot work for detecting the presence of an aromatic hydrocarbon.Explain. (b) Write a series of reactions leading topara-bromoethylbenzene, beginning with benzene andusing other reagents as needed. What isomeric side productsmight also be formed?arrow_forward(A) what are the 'Four criteria (rules) for aromaticity'? (b) Explain aromatic, antiaromatic, nonaromatic using 'Criteria for aromaticiy' and draw chemical structures of each example.arrow_forward
- (a) Name the reactant (including E/Z configuration) and draw the structure of the major product for the following reaction. + HBr (b) Explain your answer for the product in part (a), and include the structure of the carbocation intermediate in your explanation. (c) Draw the mechanism for the reaction in part (a), showing all intermediates and electron movement with arrows.arrow_forward(b) Addition of HBr to the alkene in the presence of peroxide form radical intermediates. Based on the following reaction, use the curved arrows to HBr B (preferred product) ROOR (i) show the initiation step of this reaction. (ii) draw the possible structures of the two radicals formed in the propagation step. (ii) explain the formation of the preferred product B.arrow_forwardAlthough benzene is normally written with three double bonds, benzene is not reactive towards many reagents that alkenes normally react with. This lack of reactivity can be explained by the unusual stability created by cyclic conjugation. First, (i) describe at least one of the physical properties of benzene that demonstrates how the true structure of benzene does match the way the structure is normally written. Then, (ii) explain how the unusual stability of benzene can be demonstrated by its thermodynamic properties through some form of experiment. Be sure to (iii) include an appropriately labeled diagram as part of your answer (you do not have to quote any numerical values).arrow_forward
- (a) Explain how pyrrole is isoelectronic with the cyclopentadienyl anion.(b) Specifically, what is the difference between the cyclopentadienyl anion and pyrrole?(c) Draw resonance forms to show the charge distribution on the pyrrole structure.arrow_forward3. (a) Draw the structure of 1-ethylcyclohexene (B). (b) Draw the structures of the two possible products that can result from treating B with hydrogen bromide and very briefly explain which one will be favoured). (c) Draw the curly arrow mechanism for the formation of the favoured productarrow_forward(a) Which is the correct structure of the alkyl halide substrate? (b) Which is the correct structure of the nucleophile?arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistryChemistryISBN:9781259911156Author:Raymond Chang Dr., Jason Overby ProfessorPublisher:McGraw-Hill EducationPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
- Organic ChemistryChemistryISBN:9780078021558Author:Janice Gorzynski Smith Dr.Publisher:McGraw-Hill EducationChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningElementary Principles of Chemical Processes, Bind...ChemistryISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEY
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305957404/9781305957404_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781259911156/9781259911156_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780078021558/9780078021558_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305079373/9781305079373_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781118431221/9781118431221_smallCoverImage.gif)