The Michael reaction of silyl enol ethers or ketene silyl acetals with conjugated nitro olefins activated by Lewis acids: new synthesis of 1,4-diketones and .gamma.-oxo esters
Modifizierte Wichterle-Reaktion。Ein Weg zur Darstellung von 2-Cyclohexenonen 和 1,4-Diketonen。合成 von 4-Esren-3,17-dion 和 Dihydrojasmon
摘要:
Wahrend die Behandlung von 2-(3-Chlor-2-butenyl)-2-methylcyclohexanon mit konz。H2SO4 2,5-二甲基双环[3.3.1]non-2-en-9-on als Hauptprodukt ergab, wurde beim Erhitzen in HCO2H in Anwesenheit von HClO44a-Methyl-Δ1(8a)-2-octalon in 70 bis 98%艾格 Ausbeute erhalten。Unter diesen Bedingungen reagierten andere α(Chlorbutenyl)ketone analog und lieferten die entsprechende Annelierungsprodukte in hohen bis massigen Ausbeuten。Aus
Addition of 2-nitropropene to the chiral imine derived from 2-methylcyclopentanone and (S)-1-phenylethylamine furnished the expected Michael adduct. The latter compound was then efficiently converted into (R)-pentalenone through a Nef reaction. Condensation of the enamino ester derived from 2-carbethoxycyclopentanone and (S)-1-phenylethylamine with 1-nitropropene gave with excellent diastereo- and enantioselectivity the corresponding Michael adduct. (C) 1999 Elsevier Science Ltd. All rights reserved.
New 1,4-diketone synthesis using nitroolefins and trimethylsilyl enol ethers. A convenient regiospecific route to cyclopentenones
1,4- and 1,5-Diketones via palladium-catalyzed allylation of potassium enoxyborates
作者:Eiichi Negishi、Fen Tair Luo、Anthony J. Pecora、Augustine Silveira
DOI:10.1021/jo00162a030
日期:1983.7
Chemistry of organosilicon compounds. 148. 3-Chloro-2-(trimethylsiloxy)-1-propene as an electrophilic acetonyl equivalent. Novel regioselective synthesis of 1,4-dicarbonyl compounds