87481-47-8

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• 87463-34-1 3E,5-hexadien-1-yl prop-2-enoate 
• 73670-87-8 (E)-hexa-3,5-dien-1-ol 

Relevant academic research and scientific papers

Intramolecular Diels Alder reactions in highly organized imidazolium salt-based ionic liquid crystals

This paper describes the development of a new family of ionic liquid crystals based on imidazolium salts and their applications as media for intramolecular Diels Alder reactions. The use of highly organized smectic T phases was shown to be an efficient method to obtain the intramolecular Diels Alder product in high yields, without using high dilution conditions. The ionic liquid crystal media can be recycled in an easy procedure and reused up to at least five times, without loss of reactivity and selectivity.

Intramolecular Diels-Alder reaction of α-fluoroacrylate derivatives promoted by novel bidentate aluminum Lewis acid

Intramolecular Diels-Alder (IMDA) reaction of α-fluoroacrylate derivatives 1a-e having 1,7,9-decatrienoate system is efficiently promoted by the novel bidentate Lewis acid A generated in situ by mixing 3,3′,5,5′-tetrabromo-1,1′-biphenyl-2,2′-diol (Br 4BIPOL, 1 mol) and trimethylaluminum (2 mol). The IMDA reaction of α-fluoroacrylates proceeds via endo-boat transition state as in the case of the corresponding non-fluorinated acrylate.

Intramolecular Diels-Alder Reactions of Ester-Tethered 1,7,9-Decatrienoates: Bis[chloro(methyl)aluminum]trifluoromethanesulfonamide as a Catalyst

(Matrix Presented) The intramolecular Diels-Alder reaction of 1,7,9-decatrienoate derivative with an ester tether is efficiently catalyzed by the bidentate Lewis acid, bis-aluminated trifluoromethanesulfonamide.

Enantioselective oxazaborolidinium-catalyzed Diels-Alder reactions without CH·...O hydrogen bonding

(Chemical Equation Presented) All cis-tems go! The first detailed computational investigations into the title reaction validate Corey's two pre-transition-state models and reveal a third Lewis acid coordination mode (see picture), which operates for esters having s-cis C=C-C=O groups. The new pre-transition-state model explains the unexpected enantioselectivity witnessed for several Diels-Alder reactions and does not involve a C-H...O hydrogen bond.

Intramolecular Diels-Alder reactions of ester linked 1,3,9-decatrienes: Cis/trans selectivity in thermal and Lewis acid promoted reactions of ethylene-tethered and benzo-tethered systems

High cis (i.e., endo) diastereoselectivities are witnessed in heat-promoted intramolecular Diels-Alder (IMDA) reactions of ethylene-tethered hexadienyl acrylates. The cis stereoselectivity is improved by promotion with Et 2AlCl. The first examples of Et2AlCl catalyzed intramolecular Diels-Alder reactions of ester-activated dienophiles are reported. In contrast, the corresponding benzo-tethered hexadienyl acrylates undergo moderately trans (i.e., exo) selective IMDA reactions. Very high trans stereoselection is obtained upon promotion with ATPH. The outcomes of these reactions are essentially insensitive to dienophile (C10) geometry and substitution. DFT (B3LYP/6-31+G(d)) computed cis/trans product distributions-based on Boltzmann transition structure populations-are in good agreement with the experimental results. These computational investigations provide useful insights into the origins of stereoselection in these systems. The stereoselectivity exhibited by the ethylene-tethered hexadienyl acrylates is ascribed to stabilizing secondary orbital interactions at play in the cis-transition structures (TSs). In the benzo-tethered series, this effect is overridden by stabilizing π-conjugative interactions, between the benzo moiety and the 1,3-diene component, which are stronger in trans TSs, compared to the cis TSs. The computed TS geometries generally exhibit advanced peripheral bond forming asynchronicity, with the tether carbonyl group in conjugation with the dienophile. Such TS features significantly weaken the stereodirecting influence of terminal dienophile substituents.

Intramolecular Diels-Alder reaction of 1,7,9-decatrienoates catalyzed by indium(III) trifluoromethanesulfonate in aqueous media

The intramolecular Diels-Alder reaction of ester-tethered 1,7,9-decatrienoate derivatives in a mixture of water and 2-propanol was catalyzed by indium(III) triflate to give the cycloadducts in good yield with perfect endo-selectivity.

Efficient intramolecular Diels-Alder reactions of ester-tethered 1,7,9-decatrienoates catalyzed by bis-aluminated trifluoromethanesulfonamide

Bis-aluminated trifluoromethanesulfonamide generated in situ by mixing TfNH2 (1 mol) and methylaluminum reagent (2 mol) is an effective catalyst for the IMDA reaction of ester-tethered 1,7,9-decatrienoates. Graphical Abstract

Aspects of the Intramolecular Diels-Alder Reactions of Some 1,3,9-Trienic Amides, Amines, and Esters. An Approach to the Pentacyclic Skeleton of the Yohimboid Alkaloids

The intramolecular cycloadditions of a number of 1,3,9-tienes containing an amide, amine, or ester function in the chain linking the dienophile and the diene were examined, and a general preference for the formation of cis cycloadducts was observed.Thus, the aza trienes 7b-h were found to undergo intramolecular Diels-Alder reaction upon thermolysis at temperatures ranging from 25 to 275 deg C to give mixtures of the cis- and trans-hydroisoquinolines 9b-h and 10b-h, respectively, in ratios that varied from about 1.1:1 to 8:1.Thermolysis of the pentadienamide 34 produced the cis- and trans-hydroisoquinolines 35 and 36 (1.6:1).Interestingly, the aza trienes 13 and 14 in which the internal double bond is Z appear to suffer extensive isomerization, presumably via 1,5-hydrogen migration, prior to cyclization to provide isomeric trienes, which have not been isolated but have been tentatively identified as 22 and 25 since they afford corresponding mixtures of the cis- and trans-hydroisoindoles 20/21 and 23/24 as the principle cycloadducts; only small amounts of the expected cis-hydroisoquinolines 9e and 9h were obtained in these thermolyses.In order to demonstrate the feasibility of applying intramolecular Diels-Alder reactions of aza trienes to the syntheses of alkaloids containing a hydroisoquinoline ring, the trans-hydroisoquinoline 10d was converted to the yohimbine-related compounds 38 and 39 by cyclization with POCl3 followed by either catalytic hydrogenatin or hydride reduction of the intermediate iminium salt.The reactivity of the related esters 40-42 toward intramolecular cycloaddition was also briefly examined, and it was found that only the acrylate 41 underwent cyclization at temperatures below 275 deg C.