Intramolecular <i>Wittig</i> Reaction: A New Synthesis of (<i>S</i>)‐Pyrrolam A

Majik, Mahesh S.; Parameswaran, P.S.; Tilve, Santosh G.

doi:10.1002/hlca.200890163

Cited by 15 publications

(4 citation statements)

References 26 publications

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“…To circumvent the problem, the selenenyl deriva- In an effort to establish a more practical and scalable route to pyrrolam A, another synthetic approach involving phosphorus ylide chemistry simultaneously emerged from our group, which demonstrates the practicability of intramolecular Wittig reaction for the construction of the bicyclic skeleton of (S)-pyrrolam A [(+)-1] (Scheme 7). 24 Prolinol was converted into (S)-N-(bromoacetyl)prolinol (34) using bromoacetyl bromide. Oxidation of (S)-N-(bromoacetyl)prolinol (34) followed by treatment with triphenylphosphine gave the corresponding Wittig salt 36.…”

Section: Chiral Pool Methods: Proline As a Starting Materialsmentioning

confidence: 99%

Pyrrolizidine Alkaloids Pyrrolams A-D: A Survey of Synthetic Efforts, Biological Activity, and Studies on Their Stability

Majik

Tilve

2012

Synthesis

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Pyrrolam A is a microbial metabolite, structurally related to plant alkaloids of the necine-type, and was isolated from the bacterial strain of Streptomyces olivaceus along with the related alkaloids pyrrolams B-D. The synthesis of (S)-and (R)-pyrrolam A has attracted the attention of chemists in recent years, with 10 syntheses reported to date. The reported routes utilize the advantages of chiral proline as a starting material, with pyrrolidine nucleus as source of one of the two rings on which the second ring has been constructed. This review discusses the isolation of the deceptively simple pyrrolizidine alkaloid pyrrolam A, its biological studies, synthesis, and computational studies on the stability of the double bond in its strained bicyclic skeleton. In addition, the synthesis of pyrrolams B-C and their relationship to pyrrolam A is also discussed.

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Section: Chiral Pool Methods: Proline As a Starting Materialsmentioning

confidence: 99%

Pyrrolizidine Alkaloids Pyrrolams A-D: A Survey of Synthetic Efforts, Biological Activity, and Studies on Their Stability

Majik

Tilve

2012

Synthesis

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“…216 Starting from Lproline, the key phosphorane was generated in few steps and converted in situ into pyrrolam A with 41% yield (Scheme 26). Hewson and his group reported the preparation synthesis of sulpinidine applying the same approach via a Wittig-process.…”

Section: Wittig Reactionmentioning

confidence: 99%

Synthetic Strategies towards the Azabicyclo[3.3.0]-Octane Core of Natural Pyrrolizidine Alkaloids. An Overview

Martinez

Belouezzane

Pinto

et al. 2016

Organic Preparations and Procedures International

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“…This type of alkaloids, having the pyrrolidine pattern in their structure, is widespread among the secondary metabolites, but also presents important biological activities . ( S )‐Pyrrolam A 23 is therefore a popular target and one strategy towards his synthesis involves an intramolecular Wittig reaction as a key step . The ( S )‐1‐(2‐bromoacetyl)pyrrolidine‐2‐carbaldehyde 21 is transformed into ( S )‐pyrrolam A 23 , without isolation of the intermediate ( S )‐1‐[2‐(triphenylphosphoranylidene)acetyl]pyrrolidine‐2‐carbaldehyde 22 (Scheme ).…”

Section: Total Synthesis Of Natural Heterocyclic Compoundsmentioning

confidence: 99%

Applications of the Wittig Reaction on the Synthesis of Natural and Natural‐Analogue Heterocyclic Compounds

2018

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More than sixty years after its discovery, the Wittig reaction still is a powerful tool to create carbon–carbon double bonds. The large diversity of high‐yielding and stereoselective reactions that can be achieved, even for highly functionalized molecules, is presented, demonstrating that the Wittig reaction is an efficient and attractive strategy in synthetic organic chemistry. The principles of the reaction will be briefly presented and discussed, but the focus will be on the most recent reports using this reaction in the synthesis of heterocyclic compounds. A comprehensive discussion on its application in the total synthesis of natural products and in the synthesis of natural analogues will be presented. Emphasis will be given to important organic molecules that present interesting biological activities. The purpose of this short review is to highlight the advances in this general area by presenting such newer applications in organic synthesis and eventually guide future researchers.

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Intramolecular Wittig Reaction: A New Synthesis of (S)‐Pyrrolam A

Abstract: A straightforward synthesis of (S)-pyrrolam A is described. The synthesis involves in situ generation of the phosphorane 3, followed by an intramolecular Wittig reaction to furnish (S)-pyrrolam A.

Cited by 15 publications

References 26 publications

Pyrrolizidine Alkaloids Pyrrolams A-D: A Survey of Synthetic Efforts, Biological Activity, and Studies on Their Stability

Pyrrolizidine Alkaloids Pyrrolams A-D: A Survey of Synthetic Efforts, Biological Activity, and Studies on Their Stability

Synthetic Strategies towards the Azabicyclo[3.3.0]-Octane Core of Natural Pyrrolizidine Alkaloids. An Overview

Applications of the Wittig Reaction on the Synthesis of Natural and Natural‐Analogue Heterocyclic Compounds

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