(a)
Interpretation: The kind of sigmatropic rearrangement that occurs in each of the given reactions has to be given.
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.
(b)
Interpretation: Using arrows the electron rearrangement takes place in the given reactions has to be shown.
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.
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ORGANIC CHEM ALC PKG
- The use of curved arrows is a powerful tool that illustrates even complex reactions. a.Add curved arrows to show how carbocation A is converted to carbocation B. Label each new σ bond formed. Similar reactions have been used in elegant syntheses of steroids. b.Draw the product by following the curved arrows. This reaction is an example of a [3,3] sigmatropic rearrangement, as we will learn in Chapter 25.arrow_forwardShow the stepwise mechanism for the entire reaction below, including all arrows and intermediates. Your EAS should show at least one resonance form for the sigma complex.arrow_forward3) If the product of an SN1 or Free radical reaction contains a stereocenter then a _______________ mixture occurs. Complete the sentence above and explain why this occurs. 4) List and explain the 3 steps of a free radical reaction.arrow_forward
- Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning