Asymmetric Total Syntheses of (+)-Mycoepoxydiene and Related Natural Product (−)-1893A:  Application of One-Pot Ring-Opening/Cross/Ring-Closing Metathesis to Construct Their 9-Oxabicyclo[4.2.1]nona-2,4-diene Skeleton

2004 ◽  
Vol 69 (25) ◽  
pp. 8789-8795 ◽  
Author(s):  
Ken-ichi Takao ◽  
Hiroyuki Yasui ◽  
Shun Yamamoto ◽  
Daisuke Sasaki ◽  
Soujiro Kawasaki ◽  
...  
Keyword(s):  
Natural Product ◽  
Ring Opening ◽  
Ring Closing Metathesis ◽  
One Pot ◽  
Total Syntheses

One-Pot Tandem Ring-Opening and Ring-Closing Metathesis Polymerization of Disubstituted Cyclopentenes Featuring a Terminal Alkyne Functionality

2020 ◽  
Vol 53 (11) ◽  
pp. 4330-4337
Author(s):  
Santhosh Kumar Podiyanachari ◽  
Salvador Moncho ◽  
Edward N. Brothers ◽  
Saeed Al-Meer ◽  
Mohammed Al-Hashimi ◽  
...  
Keyword(s):  
Ring Opening ◽  
Terminal Alkyne ◽  
Ring Closing Metathesis ◽  
One Pot ◽  
Metathesis Polymerization

scholarly journals A Short Stereoselective Synthesis of Racemic 2-Epicalvine

2010 ◽  
Vol 5 (8) ◽  
pp. 1934578X1000500
Author(s):  
Basem A. Moosa ◽  
Shaikh A. Ali
Keyword(s):  
Natural Product ◽  
Vinyl Ether ◽  
Ring Opening ◽  
Stereoselective Synthesis ◽  
Cycloaddition Reaction ◽  
One Pot ◽  
Ladybird Beetle

The cycloaddition reaction of 6-pentyl-3,4,5,6-tetrahydropyridine 1-oxide with butyl vinyl ether was used as a key step in the short stereoselective racemic synthesis of ladybird beetle alkaloid, 2-epicalvine. The cycloadduct was subjected to quaternization with 2-bromoethanol, followed by ring opening and lactonization to afford the natural product in a one-pot reaction.

scholarly journals Recent applications of ring-rearrangement metathesis in organic synthesis

2015 ◽  
Vol 11 ◽  
pp. 1833-1864 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Milind Meshram ◽  
Priti Khedkar ◽  
Shaibal Banerjee ◽  
Deepak Deodhar
Keyword(s):  
Organic Synthesis ◽  
Ring Opening ◽  
Bond Formation ◽  
Ring Closing Metathesis ◽  
One Pot ◽  
Economic Process ◽  
Conventional Methods

Ring-rearrangement metathesis (RRM) involves multiple metathesis processes such as ring-opening metathesis (ROM)/ring-closing metathesis (RCM) in a one-pot operation to generate complex targets. RRM delivers complex frameworks that are difficult to assemble by conventional methods. The noteworthy point about this type of protocol is multi-bond formation and it is an atom economic process. In this review, we have covered literature that appeared during the last seven years (2008–2014).

Masked Bisketenes as Diels–Alder Dienes

2020 ◽  
Author(s):  
Isuru Dissanayake ◽  
Jacob Hart ◽  
Emma Becroft ◽  
Christopher Sumby ◽  
Christopher Newton
Keyword(s):  
Natural Product ◽  
Ring Opening ◽  
Alder Reaction ◽  
Diels Alder ◽  
Natural Product Synthesis ◽  
One Pot ◽  
Neuroprotective Agent ◽  
Mild Conditions ◽  
Diels Alder Reaction

<div> <div> <div> <p>2,5-Bis(<i>tert</i>-butyldimethylsilyloxy)furans are established as masked vicinal bisketenes for application as dienes in the Diels–Alder reaction. Cycloaddition with olefinic dienophiles, under exceptionally mild conditions, enables convergent access to highly substituted <i>para</i>-hydroquinones in unprotected form via a one-pot Diels–Alder/ring-opening/tautomerization sequence. The synthesis of <i>para</i>-benzoquinones from acetylenic dienophiles, including benzynes, is also demonstrated, and 2,5-bis(<i>tert</i>-butyldimethylsilyloxy)pyrroles are established as competent dienes for the synthesis of <i>para</i>-iminoquinones. Application in natural product synthesis enables gram-scale access to the neuroprotective agent (±)-indanostatin. </p> </div> </div> </div>

Bisketene Equivalents as Diels–Alder Dienes

2020 ◽  
Author(s):  
Isuru Dissanayake ◽  
Jacob Hart ◽  
Emma Becroft ◽  
Christopher Sumby ◽  
Christopher Newton
Keyword(s):  
Natural Product ◽  
Ring Opening ◽  
Alder Reaction ◽  
Diels Alder ◽  
Natural Product Synthesis ◽  
One Pot ◽  
Neuroprotective Agent ◽  
Mild Conditions ◽  
Diels Alder Reaction

<div> <div> <div> <p>2,5-Bis(<i>tert</i>-butyldimethylsilyloxy)furans are established as vicinal bisketene equivalents for application as dienes in the Diels–Alder reaction. Cycloaddition with olefinic dienophiles, under exceptionally mild conditions, enables convergent access to highly substituted <i>para</i>-hydroquinones in unprotected form via a one-pot Diels–Alder/ring-opening/tautomerization sequence. The synthesis of <i>para</i>-benzoquinones from acetylenic dienophiles, including benzynes, is also demonstrated, and 2,5-bis(<i>tert</i>-butyldimethylsilyloxy)pyrroles are established as competent dienes for the synthesis of <i>para</i>-iminoquinones. Application in natural product synthesis enables gram-scale access to the neuroprotective agent (±)-indanostatin.</p> </div> </div> </div>

A One-Pot Chemoenzymatic Synthesis of (2S,4R)-4-Methylproline Enables the First Total Synthesis of Antiviral Lipopeptide Cavinafungin B

2018 ◽  
Author(s):  
Christian R. Zwick ◽  
Hans Renata
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Complex Molecule ◽  
Molecular Target ◽  
Chemoenzymatic Synthesis ◽  
General Strategy ◽  
One Pot

We report an efficient ten-step synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (Rink-Boc-ATG-resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner.This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

Metal-Free Photoredox-Catalyzed C–H/C–H Coupling of Arenes Enabled by Interrupted Pummerer Activation

2019 ◽  
Author(s):  
Miles Aukland ◽  
Mindaugas Šiaučiulis ◽  
Adam West ◽  
Gregory Perry ◽  
David Procter
Keyword(s):  
Natural Product ◽  
Selective Reduction ◽  
Cross Coupling ◽  
One Pot ◽  
Complex Molecules ◽  
Pummerer Reaction ◽  
Metal Free ◽  
Bond Forming ◽  
Coupling Partner ◽  
Bioactive Natural Product

<p>Aryl–aryl cross-coupling constitutes one of the most widely used procedures for the synthesis of high-value materials, ranging from pharmaceuticals to organic electronics and conducting polymers. The assembly of (hetero)biaryl scaffolds generally requires multiple steps; coupling partners must be functionalized before the key bond-forming event is considered. Thus, the development of selective C–H arylation processes in arenes, that side-step the need for prefunctionalized partners, is crucial for streamlining the construction of these key architectures. Here we report an expedient, one-pot assembly of (hetero)biaryl motifs using photocatalysis and two non-prefunctionalized arene partners. The approach is underpinned by the activation of a C–H bond in an arene coupling partner using the interrupted Pummerer reaction. A unique pairing of the organic photoredox catalyst and the intermediate dibenzothiophenium salts enables highly selective reduction in the presence of sensitive functionalities. The utility of the metal-free, one-pot strategy is exemplified by the synthesis of a bioactive natural product and the modification of complex molecules of societal importance.</p>

An Overview of the One-pot Synthesis of Imidazolines

2020 ◽  
Vol 24 (20) ◽  
pp. 2341-2355
Author(s):  
Thaipparambil Aneeja ◽  
Sankaran Radhika ◽  
Mohan Neetha ◽  
Gopinathan Anilkumar
Keyword(s):  
Asymmetric Catalysis ◽  
Organic Compounds ◽  
Ring Opening ◽  
Ecological Impact ◽  
Chiral Auxiliary ◽  
One Pot ◽  
One Pot Synthesis ◽  
The One ◽  
Synthetic Intermediate ◽  
Heterocyclic Moiety

One-pot syntheses are a simple, efficient and easy methodology, which are widely used for the synthesis of organic compounds. Imidazoline is a valuable heterocyclic moiety used as a synthetic intermediate, chiral auxiliary, chiral catalyst and a ligand for asymmetric catalysis. Imidazole is a fundamental unit of biomolecules that can be easily prepared from imidazolines. The one-pot method is an impressive approach to synthesize organic compounds as it minimizes the reaction time, separation procedures, and ecological impact. Many significant one-pot methods such as N-bromosuccinimide mediated reaction, ring-opening of tetrahydrofuran, triflic anhydrate mediated reaction, etc. were reported for imidazoline synthesis. This review describes an overview of the one-pot synthesis of imidazolines and covers literature up to 2020.

Construction the A-B bicyclic ring structure of Stemocurtisisne

2020 ◽  
Vol 17 ◽  
Author(s):  
Duc Dau Xuan
Keyword(s):  
Glutamic Acid ◽  
Natural Product ◽  
Mannich Reaction ◽  
Boronic Acid ◽  
Ring Opening ◽  
Ring Structure ◽  
Starting Material ◽  
Epoxide Ring ◽  
Epoxide Ring Opening

: The synthesis of the A-B bicyclic ring structure 3 of the natural product Stemocurtisine is described. The synthesis was accomplished in seven synthetic steps from commercially available L-glutamic acid. The key step involved a borono-Mannich reaction between the hemiaminal 6 and trans-β-styryl boronic acid and trans-β-styrylpotassiumtrifluoroborate to prepare the cis diene 4. Attempts to prepare the A-B-C ring compound 2 via intramolecular epoxide ring opening followed by rearangement under different basic conditions were unsuccessful. Only unreactive starting material was recovered.

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