Sigmatropic Reactions in Carbanions. II. The Rearrangement of Allylic Ammonium Ylides

Rautenstrauch, Valentin

doi:10.1002/hlca.19720550645

Cited by 23 publications

(6 citation statements)

References 17 publications

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“…Commercially available 2.5  nBuLi and 1.3  sBuLi (both from Aldrich) were titrated using the [1,10]phenanthroline method. [30] (Z)-1-trimethylsiloxybuta-1,3-diene (7) [31] and 4-tertbutyl-1-(trimethylsiloxy)cyclohexene were prepared according to literature procedures (ref. [10,32] respectively).…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Heck Reactions of Ethenyl- and (Z)-Butadien-1-yl Nonaflate Obtained by the Fragmentation of Furan Derivatives

2001

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Keywords: Carbanions / Silyl enol ether / Fluorides / Alkenyl nonaflates / Heck reactionThe nonaflation of lithium enolates or of silyl enol ethers, formally derived from acetaldehyde or crotonaldehyde, with nonafluorobutanesulfonyl fluoride gave ethenyl nonaflate (1b) and (Z)-buta-1,3-dien-1-yl nonaflate (2) in good yields. The required enolates were obtained by aldehyde-free routes by the lithiation of tetrahydrofuran or 2,5-dihydrofuran followed by the cyclofragmentation of the metallated heterocycles. The application of this approach to the synthesis of allenyl nonaflate 3 failed, presumably due to the intrinsic instability of this allene derivative. The nonaflates 1b and 2 were also prepared by the fluoride-catalysed reaction of the

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Section: Resultsmentioning

confidence: 99%

Synthesis and Heck Reactions of Ethenyl- and (Z)-Butadien-1-yl Nonaflate Obtained by the Fragmentation of Furan Derivatives

2001

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“…The [2,3]-sigmatropic rearrangement is as ymmetry-allowed reactionand therefore proceeds through aconcert-ed mechanism with lower activatione nergies compared with the [1,2]-reaction pathway. [41][42][43] Although the Stevens [2,3]-rearrangement is av ery powerful transformation,o nly af ew applications in natural product synthesis are reported to date. [44][45][46][47][48] Three examples are summarized in Scheme 2.…”

Section: Stevens Rearrangement Of Ammonium Ylidesmentioning

confidence: 99%

“…This type of rearrangement is called a Stevens [2,3]‐rearrangement (Scheme B). The [2,3]‐sigmatropic rearrangement is a symmetry‐allowed reaction and therefore proceeds through a concerted mechanism with lower activation energies compared with the [1,2]‐reaction pathway …”

Section: Introductionmentioning

confidence: 99%

Formal Total Synthesis of (±)‐Strictamine by [2,3]‐Sigmatropic Stevens Rearrangements

Eckermann

Breunig

Gaich

2017

Chemistry A European J

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To date, more than 100 congeners of the akuammiline alkaloid family have been isolated. Their signature structural element is a methanoquinolizidine moiety, a cage-like scaffold structurally related to adamantane. The structural variations of the family members originate from oxidative processes that mostly trigger rearrangements of the methanoquinolizidine motif. The family of the akuammiline alkaloids is best represented by strictamine. It bears the least functionalized carbon skeleton of all family members without lacking the signature structural motifs. Herein, we report the formal synthesis of strictamine through a Stevens [2,3]-sigmatropic rearrangement as a key step and the synthetic pitfalls related with its synthesis.

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“…Wir konnten damit im Gegensatz zu JENNY und DRUEY [4] aber in Ubereinstimmung mit RAUTER'STRAUCTT [5]…”

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Zur Einwirkung starker Basen auf quartäre Methallyl‐ammoniumverbindungen. IV [1]. Die basen‐initiierte Umlagerung von Dimethyl‐benzyl‐methallyl‐ammoniumjodid

1977

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Es wird die Konkurrenz von STEVENS‐ und SOMMELET‐Umlagerung bei der Einwirkung von Natriumamid, Methylsulfinyl‐carbanion und Butyllithium auf Dimethyl‐benzyl‐methallyl‐ammoniumjodid untersucht. Mit allen 3 Basensystemen wurden ein SOMMELET‐ und zwei STEVENS‐Umlagerungsprodukte erhalten. Mit Natriumamid überwog das Produkt der [3, 2]‐SOMMELET‐Umlagerung, mit Methylsulfinyl‐carbanion das der [1, 2]‐ und mit Butyllithium das der [3, 2]‐ STEVENS‐Umlagerung.

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Sigmatropic Reactions in Carbanions. II. The Rearrangement of Allylic Ammonium Ylides

Abstract: Two representative cases of the [2, 3] sigmatropic rearrangement are described, and the mechanism of this reaction is discussed.

Cited by 23 publications

References 17 publications

Synthesis and Heck Reactions of Ethenyl- and (Z)-Butadien-1-yl Nonaflate Obtained by the Fragmentation of Furan Derivatives

Synthesis and Heck Reactions of Ethenyl- and (Z)-Butadien-1-yl Nonaflate Obtained by the Fragmentation of Furan Derivatives

Formal Total Synthesis of (±)‐Strictamine by [2,3]‐Sigmatropic Stevens Rearrangements

Zur Einwirkung starker Basen auf quartäre Methallyl‐ammoniumverbindungen. IV [1]. Die basen‐initiierte Umlagerung von Dimethyl‐benzyl‐methallyl‐ammoniumjodid

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