The Diels-Alder cycloadditions of cyclopentadiene and 2,3-dimethyl-1,3-butadiene to a range of 2-thio-3-chloroacrylamides under thermal, catalytic and microwave conditions is described. The influence of reaction conditions on the outcome of the cycloadditions, in particular the stereoselectivity and reaction efficiency, is discussed. While the cycloadditions have been attempted at the sulfide, ...

Background Oral Allergy Syndrome (OAS) is an IgE-mediated allergic response to fresh fruits, nuts and vegetables caused by cross-reactivity between pollen allergens and structurally similar food proteins. Alder pollen is a prominent allergen in coastal British Columbia, present at high levels from FebruaryApril. We hypothesized that this exposure may lead to increased prevalence of Alder pollen...

Initially, lasubin II was synthesized diastereoselectively in racemic form [3]. Asymmetric syntheses of lasubin II were achieved based on stereoselective transformations of enantiomerically pure substrates [4] or, for example, via a diastereoselective aza-Diels-Alder reaction using a resolved chiral arylaldehyde tricarbonylchromium complex [5]. Recently, an enantioselectively catalyzed aza-Diel...

Studies toward the enantiospecific total synthesis of rhodexin A via a very hindered inverse electron demand Diels-Alder reaction are described. The C8-diastereomer of the fully elaborated tetracyclic core of rhodexin A, 23, was prepared in good yield and excellent selectivity using as the key step the stepwise Diels-Alder reaction of the very hindered dienone 3 and the silyl enol ether 4 catal...

Two catalysts, Me(2)AlNTf(2) and MeAl(NTf(2))(2), derived from the mixing of trimethylaluminum with triflimide, proved to be highly effective catalysts in hindered Diels-Alder reactions, generating the desired Diels-Alder cycloadducts from both hindered 2-silyloxydienes and hindered dienophiles. Thus reaction of 1 with 2 afforded the hindered cycloadduct 4 in excellent yield in 0.5-1.5 h at -40...

Annual renewable resource potential of medicinal plant materials in the Republic Belarus - Black alder leaves and Gray has been studied. It was found that average annual supply black for last 6 years 7845898,5 tons gray 733257,5 tons. The stock is almost 10 times as high leaves. During storing wood from 2015 to 2019, on 65,623,8 dry were unused by-product. Annually sylvulas are created forest f...

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...

A large number of dienes and dienophiles have been employed in the Diels–Alder reaction to produce cyclohexene products with high facial, regio-, stereo-, and enantioselectivity. The reactions work best when the dienophile is substituted with an electron-withdrawing group. However, often in synthesis, the addition of an ethylene unit to a diene is necessary, and the normal cycloaddition with et...

Substituted 3,4-dihydro-1,8-naphthyridin-2(1H)-ones have been synthesized with the inverse electron-demand Diels-Alder reaction from 1,2,4-triazines bearing an acylamino group with a terminal alkyne side chain. Alkynes were first subjected to the Sonogashira cross-coupling reaction with aryl halides, the product of which then underwent an intramolecular inverse electron-demand Diels-Alder react...

Density Functional Theory has been used to model the Diels-Alder reactions of the fullerene fragments triindenetriphenilene and pentacyclopentacorannulene with ethylene and 1,3-butadiene. The purpose is to prove the feasibility of using Diels-Alder cycloaddition reactions to grow fullerene fragments step by step, and to dimerize fullerene fragments, as a way to obtain C₆₀. The dienophile charac...