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1. quizlet.com › 510784572 › sigmatropic-rearrangementsSigmatropic Rearrangements Flashcards - Quizlet

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   Study with Quizlet and memorize flashcards containing terms like sigmatropic rearrangement, (1,n) hydrogen shifts, (1,3) (1,5) (1,7) etc. H-shifts and more. hello quizlet Home

2. quizlet.com › 334494342 › l3-pericyclics-sigmatropicL3 Pericyclics: Sigmatropic rearrangements Flashcards | Quizlet

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   Study with Quizlet and memorize flashcards containing terms like What is a sigmatropic rearrangement?, How do you determine what type of shift is occurring by counting?, What are [1,2] hydride shifts commonly used for? and more.

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4. quizlet.com › 806130400 › sigmatropic-rearrangementssigmatropic rearrangements Flashcards - Quizlet

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   Study with Quizlet and memorize flashcards containing terms like number from the bond to be broken. end numbers tell what type of rearrangement it is., 3,3 rearrangements -, claisen and more.

5. quizlet.com › gb › 171589818Sigmatropic Rearrangements Flashcards - Quizlet

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   Study with Quizlet and memorize flashcards containing terms like Sigmatropic Rearrangements, When does a suprafacial rearrangement take place, When does an antarafacial rearrangement take place and more.

6. chem.libretexts.org › Courses › Smith_College29.8: Some Examples of Sigmatropic Rearrangements

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   Jan 15, 2023 · Another important example of a [3,3] sigmatropic reaction is the cope rearrangement. This reaction converts between isomers of a 1,5-hexadiene through a cyclic transition state. Both Cope and Claisen rearrangements involve the movement of six electrons which means they both react by suprafacial pathways under thermal conditions.

7. openstax.org › 30-7-sigmatropic-rearrangements30.7 Sigmatropic Rearrangements - Organic Chemistry - OpenStax

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   A sigmatropic rearrangement, the third general kind of pericyclic reaction, is a process in which a σ -bonded substituent atom or group migrates across a π electron system from one position to another. A σ bond is broken in the reactant, the π bonds move, and a new σ bond is formed in the product. The σ -bonded group can be either at the ...

8. People also ask

   What is sigmatropic rearrangement reaction?

   • This is a rearrangement reaction which means that the bonds in a molecule shift between atoms without any atoms leaving or new atoms added to the molecule. In a sigmatropic reaction, a substituent moves from one part of a π-bonded system to another part in an intramolecular reaction with simultaneous rearrangement of the π system.

   Sigmatropic reaction - Simple English Wikipedia, the free encyclopedia

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   What do the numbers mean in a sigmatropic rearrangement?

   • The numbers refer to the two groups connected by the σ bond in the reactant and designate the positions in those groups to which migration occurs. For example, in the [1,5] sigmatropic rearrangement of a 1,3-diene, the two groups connected by the σ bond are a hydrogen atom and a pentadienyl group.

   30.7 Sigmatropic Rearrangements - Organic Chemistry - OpenStax

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   How are sigmatropic rearrangements controlled?

   • Like electrocyclic reactions and cycloadditions, sigmatropic rearrangements are controlled by orbital symmetries. There are two possible modes of reaction: migration of a group across the same face of the π system is suprafacial, and migration of a group from one face of the π system to the other face is antarafacial (Figure 30.12).

   30.7 Sigmatropic Rearrangements - Organic Chemistry - OpenStax

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   What is an example of a sigmatropic reaction?

   • Another important example of a [3,3] sigmatropic reaction is the cope rearrangement. This reaction converts between isomers of a 1,5-hexadiene through a cyclic transition state. Both Cope and Claisen rearrangements involve the movement of six electrons which means they both react by suprafacial pathways under thermal conditions.

   29.8: Some Examples of Sigmatropic Rearrangements

   chem.libretexts.org/Courses/Smith_College/Organic_Chemistry_(LibreTexts)/29:_Orbitals_and_Organic_Chemistry_-_Pericyclic_Reactions/29.08:_Some_Examples_of_Sigmatropic_Rearrangements

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   Which two groups are connected by the bond in a sigmatropic rearrangement?

   • For example, in the [1,5] sigmatropic rearrangement of a 1,3-diene, the two groups connected by the σ bond are a hydrogen atom and a pentadienyl group. Migration occurs to position 1 of the H group (the only possibility) and to position 5 of the pentadienyl group.

   30.7 Sigmatropic Rearrangements - Organic Chemistry - OpenStax

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   Are sigmatropic rearrangements symmetry-allowed?

   • Figure 30.12 Suprafacial and antarafacial sigmatropic rearrangements. Both suprafacial and antarafacial sigmatropic rearrangements are symmetry-allowed, but suprafacial rearrangements are often easier for geometric reasons. The rules for sigmatropic rearrangements are identical to those for cycloaddition reactions (Table 30.3).

   30.7 Sigmatropic Rearrangements - Organic Chemistry - OpenStax

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9. chem.libretexts.org › Bookshelves › Organic_Chemistry30.8: Some Examples of Sigmatropic Rearrangements

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   Sep 25, 2024 · In fact, the [1,5] suprafacial shift of a hydrogen atom across two double bonds of a π π system is a commonly observed sigmatropic rearrangements. For example, 5-methyl-1,3-cyclopentadiene rapidly rearranges at room temperature to yield a mixture of 1-methyl-, 2-methyl-, and 5-methyl-isomers. As another example, heating 5,5,5-trideuterio- (3 ...