Stereoselective intramolecular Diels–Alder reactions of 3-alkenyl(oxy)-2(1H)-pyrazinones
摘要:
Dichloropyrazinones are reacted with alkenolates or a Grignard reagent in order to tether a dienophilic side-chain at the 3-position. The compounds smoothly undergo intramolecular Diels -Alder reaction forming tricyclic ring systems. The reactions proceed completely stereoselective yielding only endo adducts. In the case of the alkenylpyrazinone, the core skeleton of the breviamides is obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.
High-Speed Microwave-Promoted Hetero-Diels−Alder Reactions of 2(1<i>H</i>)-Pyrazinones in Ionic Liquid Doped Solvents
作者:Erik Van der Eycken、Prasad Appukkuttan、Wim De Borggraeve、Wim Dehaen、Doris Dallinger、C. Oliver Kappe
DOI:10.1021/jo0263216
日期:2002.11.1
hetero-Diels-Alder reactions in a series of functionalized 2(1H)-pyrazinones were investigated under controlledmicrowave irradiation. The cycloaddition reactions were efficiently performed in sealed tubes, utilizing either a combination of 1,2-dichloroethane and a thermally stable ionicliquid, or 1,2-dichlorobenzene as reaction medium. In all cases, a significant rate-enhancement usingmicrowave flash heating
Stereoselective intramolecular Diels–Alder reactions of 3-alkenyl(oxy)-2(1H)-pyrazinones
作者:Wim M. De Borggraeve、Frederik J.R. Rombouts、Bie M.P. Verbist、Erik V. Van der Eycken、Georges J. Hoornaert
DOI:10.1016/s0040-4039(01)02188-8
日期:2002.1
Dichloropyrazinones are reacted with alkenolates or a Grignard reagent in order to tether a dienophilic side-chain at the 3-position. The compounds smoothly undergo intramolecular Diels -Alder reaction forming tricyclic ring systems. The reactions proceed completely stereoselective yielding only endo adducts. In the case of the alkenylpyrazinone, the core skeleton of the breviamides is obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.