4351-03-5Relevant articles and documents
Synthesis of γ,γ-Disubstituted Butenolides through a Doubly Vinylogous Organocatalytic Cycloaddition
Skrzyńska, Anna,Drelich, Piotr,Frankowski, Sebastian,Albrecht, ?ukasz
supporting information, p. 16543 - 16547 (2018/10/26)
A novel organocatalytic approach to γ,γ-disubstituted butenolides is described. It is based on a fully site-selective functionalization of 5-alkylidenefuran-2(5H)-ones via trienamine-mediated [4+2]-cycloaddition with α,β,γ,δ-diunsaturated aldehydes. The developed methodology proceeds with excellent stereocontrol and constitutes a unique example of trienamine chemistry with vinylogous dienophiles. Importantly, the reaction has very broad scope and allows for the introduction of substituents also in the α- or the β-position of the butenolide ring. Usefulness of the products obtained has been confirmed in the intramolecular Stetter reaction leading to polycyclic product.
Exo-selective asymmetric Diels-Alder reaction of 2,4-dienals and nitroalkenes by trienamine catalysis
Jia, Zhi-Jun,Zhou, Quan,Zhou, Qing-Qing,Chen, Peng-Qiao,Chen, Ying-Chun
, p. 8638 - 8641 (2011/11/06)
Raising the HOMO: 2,4-Dienals can react with nitroalkenes in trienamine-catalyzed asymmetric Diels-Alder reactions (see scheme). Crucial for the success is raising the HOMO energy of the diene through the introduction of appropriate substituents. The reaction exhibits unusually high enantioselectivity and exo selectivity; endo addition is possibly disfavored because of the electrostatic repulsion shown in the scheme. Copyright
Exclusive γ-regio functionalization of crotonaldehyde using γ-trimethylsilyl crotonaldimine. Application to the one pot synthesis of conjugated dienals
Bellassoued,Salemkour
, p. 4607 - 4624 (2007/10/03)
Cesium fluoride mediated reaction of γ-trimethylsilyl N-tert-butyl crotonaldimine 9 with a wide range of aldehydes takes place in DMSO at room temperature and affords exclusive γ-regio functionalized products. Heating (rt to 100°C) the δ-silyloxy imines 11 thus obtained leads, after very mild hydrolysis of the tert-butylimine function, to the conjugated dienals 14 in good yields and with excellent (E,E)-selectivities.
A New and Convenient Preparation of Conjugated Dienals
Yahata, Nobuhiro,Fujita, Makoto,Ogura, Katsuyuki
, p. 3601 - 3605 (2007/10/02)
For preparation of 5-monosubstituted or 5,5-disubstituted 2,4-dienals, 1-(methylthio)-5-(p-tolylsulfonyl)-1,3-pentadiene (4) is revealed to be an important precursor.When 5-(methylthio)-5-(p-tolylsulfonyl)-1,3-pentadiene, that is easily obtainable from (methylthio)methyl p-tolyl sulfone, was treated with silica gel, 1,5-rearrangement of p-tolylsulfonyl group occurred to give 4.The conditions for mono- or dialkylation of 4 followed by hydrolysis leading to the dienals are desribed.
New Functionalized Horner-Wadsworth-Emmons Reagents: Useful Building Blocks in the Synthesis of Polyunsaturated Aldehydes. A Short Synthesis of (+/-)-(E,E)-Coriolic Acid
Kann, Nina,Rein, Tobias,Akermark, Bjoern,Helquist, Paul
, p. 5312 - 5323 (2007/10/02)
The new Horner-Wadsworth-Emmons reagents 4 and 5 transform carbonyl compounds into 2,4-pentadienals and 3-methyl-2,4-pentadienals, respectively.Reagent 4 gives good yields of the desired products with a variety of aldehydes and ketones; reagent 5 generally gives good yields with aldehydes, but gives lower yields with ketones.The reactions proceed under mild conditions and give the products as predominantly 2E,4E isomers, with moderate to good stereoselectivity.In general, pure samples of the 2E,4E-dienals can be obtained after chromatography.Reagents 4 have been used in the key step in a short synthesis of (+/-)-13-hydroxy-9(E),11(E)-octadecanoic acid ((E,E)-coriolic aicd, 45).
Synthesis of Dienals by Condensation of Carbonyl Compounds with a new Reagent, the 4-Lithio-1-trimethylsiloxybutadiene
Contreras, Beatriz,Duhamel, Lucette,Ple, Gerard
, p. 2983 - 2990 (2007/10/02)
Carbonlyl compounds 2 are converted into conjugated dienals 3, in a one pot reaction, by a condensation with lithio-4- trimethylsiloxybutadiene, followed by a mild acidic hydrolysis.
Polyunsaturated aldehydes by direct polyvinylogation of carbonyl compounds using functionalized phosphonates.
Duhamel, Lucette,Guillemont, Jerome,Gallic, Yann Le,Ple, Gerard,Poirier, Jean-Marie,et al.
, p. 3129 - 3132 (2007/10/02)
Carbonyl compounds are converted into polyethylenic aldehydes in a one pot reaction with the anions of phosphonates 1. followed by a mild acidic hydrolysis.