Development of the Claisen Rearrangement/Organocatalytic Diels-Alder Approach for the Synthesis of Eunicellins

2014 ◽  
Vol 67 (9) ◽  
pp. 1189 ◽  
Author(s):  
Joel F. Hooper ◽  
Jonathan M. White ◽  
Andrew B. Holmes

The intramolecular Diels-Alder approach to synthesizing eunicellins has proved to be a powerful method for the synthesis of this class of natural products. The key to the success of this strategy is control over the endo/exo selectivity of the cycloaddition reaction, which we have addressed through an organocatalytic reaction employing the MacMillan imidazolidinone catalyst. This approach has been further developed to address the issue of functionality at the C8 position, and a novel scalable method for the extension of the medium-ring lactone has been developed.

2010 ◽  
Vol 63 (3) ◽  
pp. 529 ◽  
Author(s):  
Leon S.-M. Wong ◽  
Kathleen A. Turner ◽  
Jonathan M. White ◽  
Andrew B. Holmes ◽  
John H. Ryan

The synthesis of a hydroxylated vinyl-appended lactone, in five synthetic steps from tartaric acid, is reported. The C2-symmetrical bis-vinyl diol 12 was converted into the ketene acetal 14 via methylenation of the cyclic carbonate 13 or thermal elimination of benzeneselenenic acid from the selenoxide 17. In both cases, the in situ generated ketene acetal 14 underwent spontaneous Claisen rearrangement to give the nine-membered lactone (+)-15. Lactones of this type are potentially advanced precursors to simplified eleutherobin analogues or other medium-ring lactone natural products.


RSC Advances ◽  
2015 ◽  
Vol 5 (63) ◽  
pp. 50890-50912 ◽  
Author(s):  
Majid M. Heravi ◽  
Vaezeh Fathi Vavsari

Diels–Alder (D–A) reaction is undoubtedly the most powerful [4 + 2] cycloaddition reaction in organic synthesis.


ChemInform ◽  
2012 ◽  
Vol 43 (16) ◽  
pp. no-no
Author(s):  
Xiang Li ◽  
Xiaojin Zhang ◽  
Zhuoqin Yu ◽  
Xiaorong Liu ◽  
Qidong You ◽  
...  

2004 ◽  
Vol 57 (9) ◽  
pp. 895 ◽  
Author(s):  
Martin G. Banwell ◽  
Gwion J. Harfoot

The enantiomerically pure cis-1,2-dihydrocatechol 3, which is obtained in quantity by microbial dihydroxylation of toluene, has been converted over ten steps, including an initial Diels–Alder cycloaddition reaction, into the tricyclic ketone 12. Direct irradiation of a benzene solution of the latter compound affords a mixture of compounds 13 and 14 which embody the tricyclic frameworks of the sesquiterpene natural products tsugicoline A (1) and isovelleral (2), respectively.


2016 ◽  
Vol 20 (22) ◽  
pp. 2421-2442 ◽  
Author(s):  
Kévin Cottet ◽  
Maria Kolympadi ◽  
Dean Markovic ◽  
Marie-Christine Lallemand

2018 ◽  
Vol 15 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Shah Bakhtiar Nasir ◽  
Noorsaadah Abd Rahman ◽  
Chin Fei Chee

Background: The Diels-Alder reaction has been widely utilised in the syntheses of biologically important natural products over the years and continues to greatly impact modern synthetic methodology. Recent discovery of chiral organocatalysts, auxiliaries and ligands in organic synthesis has paved the way for their application in Diels-Alder chemistry with the goal to improve efficiency as well as stereochemistry. Objective: The review focuses on asymmetric syntheses of flavonoid Diels-Alder natural products that utilize chiral ligand-Lewis acid complexes through various illustrative examples. Conclusion: It is clear from the review that a significant amount of research has been done investigating various types of catalysts and chiral ligand-Lewis acid complexes for the enantioselective synthesis of flavonoid Diels-Alder natural products. The results have demonstrated improved yield and enantioselectivity. Much emphasis has been placed on the synthesis but important mechanistic work aimed at understanding the enantioselectivity has also been discussed.


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