Synthetic approaches to phorbols via the intramolecular Diels–Alder reactions of furans (IMDAF): oxygen bridge cleavage and high stereocontrol during cycloaddition using α′-benzylthio substituted furan substrates

1991 ◽  
pp. 527-530 ◽  
Author(s):  
Laurence M. Harwood ◽  
Tsutomu Ishikawa ◽  
Helen Phillips ◽  
David Watkin
Keyword(s):  
Diels Alder ◽  
Oxygen Bridge ◽  
Synthetic Approaches

Transannular Diels–Alder cyclization of a substituted 13-membered macrocyclic triene. An approach to the A.B.C.[6.6.5] rings of the Veratrum alkaloids

1992 ◽  
Vol 70 (9) ◽  
pp. 2335-2349 ◽  
Author(s):  
Miguel Quimpère ◽  
Luc Ruest ◽  
Pierre Deslongchamps
Keyword(s):  
Diels Alder ◽  
Oxygen Bridge ◽  
Veratrum Alkaloids ◽  
Tricyclic Compound

The synthesis and Diels–Alder cyclization of a substituted macrocyclic 13-membered triene 45 is described. Tricyclic compound A.B.C.[6.6.5] 46 having ring junctions of cis-anti-cis (CAC) stereochemistry was used to investigate the possibility of introducing a hemiketal oxygen bridge between positions 9 and 4 of the Veratrum alkaloid skeleton.

Synthetic Approaches towards [1]Benzopyrano [4,3-b]Thieno[2,3-e]Pyridines via Intramolecular Diels-Alder Reactions of 1,2,4-Triazines

2002 ◽  
Vol 2002 (2) ◽  
pp. 60-61 ◽  
Author(s):  
Yehia A. Ibrahim ◽  
Balkis Al-Saleh
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

Efficient syntheses are reported of [1]benzopyrano[4,3-b]thieno[2,3-e]pyridines (20), by the application of an intramolecular Diels–Alder reaction employing the intermediate appropriately designed functionalised thieno [3,2-e][1,2,4]triazines.

scholarly journals Synthetic approaches to haplophytine. 2. Synthesis of 4-methylamino-1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)butan-1-one

1983 ◽  
Vol 61 (6) ◽  
pp. 1126-1131 ◽  
Author(s):  
David Aaron Schwartz ◽  
Peter Yates
Keyword(s):  
Furan Ring ◽  
Alder Reaction ◽  
Diels Alder ◽  
Acid Moiety ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

Approaches to the synthesis of compounds related to the 7-aryl-7-[3-(1-hydroxy-2-aminophenyl)]-9-methylamino-5,6-dioxononanoic acid moiety (3) of the alkaloid haplophytine and its dihydrobromide are described. Treatment of the dianion of phenyl (o-pivaloylamidophenyl)methane with 2-furancarboxaldehyde followed by oxidation of the resulting alcohol gives 1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)ethanone (14). This on allylation gives 1-allyloxy-1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)ethene (20), which on being heated at 80–95 °C undergoes an intramolecular Diels–Alder reaction. Heating the resulting product or 20 at 165 °C converts them to the C-allylation product of 14, 1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)pent-4-en-1-one (22). Oxidation of 22 gives 4-(2-furoyl)-1,2,3,4-tetrahydro-4-phenyl-1-pivaloyl-2-quinolinol, which on Borch reduction gives 4-methylamino-1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)butan-1-one (24) and 2-(2-furanyl)-1-methyl-3-phenyl-3-(2-pivaloylamidophenyl)pyrrolidine. Compound 24 is a potential advanced intermediate for the synthesis of compounds related to 3. Experiments directed to the incorporation of a methoxyl or methylthio substituent at the C-5 position of the furan ring of 24 are also described.

A Review on Onychine and its Analogs: Synthesis and Biological Activity

2020 ◽  
Vol 17 (1) ◽  
pp. 3-22
Author(s):  
Claudia R.B. Gomes ◽  
Marcus V.N. de Souza ◽  
Victor Facchinetti
Keyword(s):  
Biological Activity ◽  
Multicomponent Reactions ◽  
Diels Alder ◽  
Synthetic Methods ◽  
Reaction Conditions ◽  
Low Concentrations ◽  
Wide Range ◽  
Intramolecular Cyclizations ◽  
Synthetic Approaches ◽  
Operational Simplicity

Background: Onychine is a 4-azafluorenone alkaloid isolated from the Annonaceae family, in low concentrations. Onychine and its analogs exhibit a wide range of pharmacological activities such as antifungal, antibacterial, anticancer, and antimalarial. Because of the high bioactivity of some 4-azafluorenone derivatives, several synthetic methods have been developed for their procurement. Objective: Considering the importance of these alkaloids, we aim to present the main synthetic approaches to onychines and its derivatives and the biological activity of some 4-azafluorenones. Methods: The most prominent methodologies for the synthesis of onychines were reviewed. Results: In this work, we cover many synthetic approaches for the synthesis of onychine and 4-azafluorenone derivatives including intramolecular cyclizations, multicomponent reactions, microwave-assisted multicomponent reactions, Diels-alder reactions, among others. Moreover, we also review the biological activity of 4-azafluorenones. Conclusion: 4-azafluorenones have risen as prominent structures in medicinal chemistry; however, most of the time, access to new derivatives involves toxic catalysts, harsh reaction conditions, and long-step procedures. Therefore, the development of new synthetic routes with more operational simplicity, simple purification procedure, good yields, and low environmental impact, is desirable.

ChemInform Abstract: Synthetic Approaches Towards Phorbols via the Ultra-High-Pressure Mediated Intramolecular Diels-Alder Reaction of Furans (IMDAF): Effect of Furan Substitution.

ChemInform ◽  
2010 ◽  
Vol 30 (34) ◽  
pp. no-no
Author(s):  
Angela C. Brickwood ◽  
Michael G. B. Drew ◽  
Laurence M. Harwood ◽  
Tsutomu Ishikawa ◽  
Pierre Marais ◽  
...  
Keyword(s):  
High Pressure ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ultra High Pressure ◽  
Diels Alder Reaction ◽  
Synthetic Approaches
Sign in / Sign up

Export Citation Format

Share Document