Reactions between conjugated dienols and maleic anhydride provide either cis-fused or trans-fused bicyclic products as major products, depending upon how the reaction is carried out. Simply mixing the two reactants together generally leads to cis-fused lactone acids in thermal reactions which proceed viaintermolecular Diels-Alder reaction followed by intramolecular esterification. Pre-forming t...

Alkyliminoacetonitrile derivatives were investigated as dienophiles in the Diels-Alder reaction. These activated imines react with dienes in intramolecular [4+2] cycloadditions to provide products with either the quinolizidine or indolizidine ring system, depending on the length of the tether connecting diene and dienophile. Quinolizidine cycloadducts are formed in good yield and with high ster...

The new polyheterocyclic compound, 2-benzyl-7-(4-chlorophenyl)-3-morpholino-6-((1-phenyl-1H-1,2,3-triazol-4-yl)methyl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one, was synthesized by a sequential combination of 4-chlorobenzaldehyde, (1-phenyl-1H-1,2,3-triazol-4-yl)methanamine, 2-isocyano-1-morpholino-3-phenylpropan-1-one, and maleic anhydride under microwave-assisted one-pot process [Ugi-Zhu/aza...

ABSTRACT Knoevenagel condensation of barbituric acids with aromatic aldehydes containing one or two formyl groups was carried out. 5-Arylidenebarbituric acids underwent smooth hetero-Diels-Alder (HDA) reactions with enol ethers to afford cis and trans diastereoisomers of pyrano[2,3-d]pyrimidine-2,4-diones and 5,5'-(1,4-phenylene)bis[2H-pyrano[2,3-d]pyrimidine-2,4(3H)-dione] derivatives in excel...

Unlike normal Diels-Alder reactions of acyclic alkadienes with alkenes, the vinylbicyclo[2.2.2]octene employed in the Baran total synthesis of vinigrol undergoes a quantitative Diels-Alder reaction with a tethered alkene at room temperature. Density functional theory calculations reveal that this unprecedented reactivity originates from a combination of preorganization, diene strain, and tether...

SpnF is the first monofunctional Diels-Alder/[6+4]-ase that catalyzes a reaction leading to both Diels-Alder and [6+4] adducts through a single transition state. The environment-perturbed transition-state sampling method has been developed to calculate free energies, kinetic isotope effects, and quasi-classical reaction trajectories of enzyme-catalyzed reactions and the uncatalyzed reaction in ...

In model studies towards the synthesis of harringtonolide, the construction of the tropone moiety via arene cyclopropanation was investigated. The installation of the lactone ring was accomplished by way of a Diels-Alder cycloaddition of various indenones and a-pyones. The incorporation of the key bridge methyl group and subsequent control of its stereochemistry is also outlined.

A domino process is described combining an ene reaction between two alkynes and a Diels-Alder cycloaddition of the vinylallene formed. The process accounts for the thermally induced cycloisomerization of macrocyclic triynes and enediynes to give fused tetracycles in a stereoselective manner.

A Diels-Alder reaction between cyclopentadiene and a variety of ketenimines is reported. A copper(I)-bis(phosphine complex catalyzes the cycloaddition across the C═N bond of the ketenimine in a [4 + 2] reaction to give an enamine intermediate that is hydrolyzed upon purification to generate aminoketones.

The furan heterocycle is a dienic reagent particularly suitable for the Diels-Alder reaction and maleimides represent a typical family of complementary reagents because of their strong dienophilic character. This paper reviews critically the studies devoted to the exploitation of the Diels Alder reaction between those moieties to synthesise macromolecular materials possessing different structur...