Concept explainers
Interpretation:
[1,3]sigmatropic migrations of hydrogen cannot occur under thermal conditions but [1,3] sigmatropic migration of carbon can. Reason for this should be explained.
Concept introduction:
Pericyclic reactions are “ any concerted reaction in which bonds are formed or brocken in a cyclic transition state”. There is a single transition state from start to finish, in contrast to a stepwise reaction.
There are mainly three types of pericyclic reactions,
- 1) Electrocyclic reactions
- 2) Cycloaddition reactions
- 3) Sigmatropic reactions
In a sigmatropic reaction “ one new sigma-bond is formed as another breaks.”
Sigmatropic rearrangement reactions are named with digits. For example a [1, 3] sigmatropic rearrangement describe a reaction in which the residue migrates from position 1 to position 3. Migration of carbon and hydrogen will occur in a sigmatropic rearrangement reaction. When hydrogen migrates in a sigmatropic rearrangement, the s orbital of the hydrogen is partially bonded to both the migration origin and the migration terminus in the transition state. Migration of hydrogen in suprafacial and antarafacial rearrangement can be represented as follows,
Migration of carbon occurs through two ways because it has a two lobed p orbital. Carbon can simultaneously interact with the migration origin and the migration terminus using one lobe of its p orbital.
Migration of carbon in suprafacial and antarafacial rearrangement can be represented as follows,
Carbon migrating with one lobe of its p orbital interacting
Carbon migrating with both lobe of its p orbital interacting
Want to see the full answer?
Check out a sample textbook solutionChapter 28 Solutions
Organic Chemistry; Modified MasteringChemistry with Pearson eText -- ValuePack Access Card; Study Guide and Student Solutions Manual for Organic Chemistry, Books a la Carte Edition (7th Edition)
- Check the box under each structure in the table that is an enantiomer of the molecule shown below. If none of them are, check the none of the above box under the table. Molecule 1 Molecule 2 Molecule 3 ----||| Molecule 4 Molecule 5 Molecule 6 none of the above mm..arrow_forwardShow work. don't give Ai generated solutionarrow_forwardCheck the box under each structure in the table that is an enantiomer of the molecule shown below. If none of them are, check the none of the above box under the table. Molecule 1 Molecule 2 Molecule 3 ----||| Molecule 4 Molecule 5 Molecule 6 none of the above mm..arrow_forward
- Use the vapor-liquid equilibrium data at 1.0 atm. for methanol-water (Table 2-8 ) for the following: If the methanol vapor mole fraction is 0.600, what is the methanol liquid mole fraction? Is there an azeotrope in the methanol-water system at a pressure of 1.0 atmospheres? If water liquid mole fraction is 0.350, what is the water vapor mole fraction? What are the K values of methanol and of water at a methanol mole fraction in the liquid of 0.200? What is the relative volatility αM-W at a methanol mole fraction in the liquid of 0.200?arrow_forwardCheck the box under each structure in the table that is an enantiomer of the molecule shown below. If none of them are, check the none of the above box under the table. || |II***** Molecule 1 | Molecule 4 none of the above Molecule 2 Molecule 3 Х mm... C ---||| *** Molecule 5 Molecule 6arrow_forwardis SiBr4 Silicon (IV) tetra Bromine? is KClO2 potassium dihypochlorite ?arrow_forward
- "יוון HO" Br CI Check the box under each structure in the table that is an enantiomer of the molecule shown below. If none of them are, check the none of the above box under the table. Molecule 1 Molecule 2 Molecule 3 Br Br Br HO OH H CI OH ✓ Molecule 4 Molecule 5 Molecule 6 CI Br יייון H Br OH OH CI Br ☐ none of the above × Garrow_forwardUS2 Would this be Uranium (II) diSulfide?arrow_forwardnomenclature for PU(SO4)3arrow_forward
- Li2CrO4 is this Lithium (II) Chromatearrow_forwardCheck the box under each structure in the table that is an enantiomer of the molecule shown below. If none of them are, check the none of the above box under the table. NH ** Molecule 1 NH Molecule 4 none of the above Х Molecule 3 Molecule 2 H N wwwwww.. HN Molecule 5 Molecule 6 HN R mw... N H ☐arrow_forwardNomenclature P4S3 Would this be tetraphsophorus tri sulfide?arrow_forward
- Principles of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage LearningPhysical ChemistryChemistryISBN:9781133958437Author:Ball, David W. (david Warren), BAER, TomasPublisher:Wadsworth Cengage Learning,