
Concept explainers
(a)
Interpretation:
An all-suprafacial [3, 3] sigmatropic rearrangement could in principle take place through either a chair-like or a boat-like transition state;
(a) According to the following results, two transition states are to be stated.
Concept introduction:
Electrocyclic reactions are a pericyclic reaction which occur intramolecularly. These reactions will result in the formation of ring compounds under the influence of heat or light. Notably, in this process one new sigma bond is formed and one old π-bond is consumed. Intriguingly, the reverse ring opening electrocyclic reaction can also be possible to occur under the same reaction mechanism but in reverse manner.
(b)
Interpretation:
When the terpene germacrone is distilled under reduced pressure at 165 °C, it is transformed to β-elemenone by a Cope rearrangement. The structure of germacrone, including its stereochemistry is to be deduced.
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. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.

Want to see the full answer?
Check out a sample textbook solution
Chapter 28 Solutions
Organic Chemistry, Ebook And Single-course Homework Access
- If a 5 film plastic film degraded in 30 days at 35C and the same film degraded in 10 days at 55 C and 2 days at 65C what would the predicted life time be at 22C for the same film?arrow_forwardno Ai walkthroughsarrow_forwardI have a aqueous solution (175 ml) of iridium trichloride containing 8,750 ppm Iridium by ICP OES analysis. What is the percent concentration of Iridium trichloride in aquous solution and provide the concentration in moles per liter, percentage by weight.arrow_forward
- no Ai walkthroughsarrow_forward136 PRACTICAL SPECTROSCOPY Compound 78 is a high-boiling liquid (boiling point 189° C) that contains halogen, but will not react with alkoxides to yield an halogen. ether. The Mass, IR, and 'H NMR spectra, along with 13C NMR data, are given below. Elemental Analysis: C, 35.32; H, 2.47; contains BC Spectral Data: doublet, 137.4 ppm; doublet, 130.1 ppm; doublet, 127.4 ppm; singlet, 97.3 ppm Absorbance Mass Spectrum Intensity 77 77 204 M + 128 40 60 80 100 120 140 160 180 m/e 200 220 280 240 260 300 Infrared Spectrum Wave Number, cm -1 4000 3000 2500 2000 1500 1300 1200 1100 1000 900 800 700 3 6 7 8 9 10 12 13 15 Wavelength, microns 'H NMR wwwww 5 Structure: www ppm, & ©2000 Brooks/Cole Publishing Com-arrow_forwardno Ai walkthroughsarrow_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





