Nouvelle voie d'acces aux β-nitroenones premiere preparation de β-nitroenones acycliques
摘要:
We describe here a new and mild method of synthesis of acyclic beta-nitroenones. Nitroepoxydes IVunderbar, prepared by epoxydation of the allylic nitroolefins IIIunderbar, react with silicagel or aluminium isopropoxide according to the substrate, to give the nitroethylenic alcohols Vunderbar. Their oxydation by PCC under sonication leads to the beta-nitroenones VIunderbar.
A new synthesis of 2-isoxazoline2-oxides starting from unsaturated nitro compounds is described. A facile and convenient preparation of β-alkyl substituted β-nitroenones and their conversion to β-nitrosulfides are recorded. Treatment of these compounds with potassium tert-butoxide at −78°C followed by immediate quenching with acetic acid provides access to 5-hydroxy-4-(phenylthio)-2-isoxazoline 2-oxides
Generation and cycloaddition reactions of substituted 2-nitro-1,3-dienes
作者:Achille Barco、Simonetta Benetti、Carmela De Risi、Carlo F. Morelli、Gian P. Pollini、Vinicio Zanirato
DOI:10.1016/0040-4020(96)00476-0
日期:1996.7
by suitable partners such as methyl acrylate, cyclopentadiene or ethyl vinyl ether. The expected cycloadducts are regiochemically formed by reaction with methyl acrylate, while the initially formed adducts with cyclopentadiene underwent thermal Cope or hetero-Cope rearrangements leading to the formation of nitro-substituted bicyclic compounds. The thermal rearrangement of the oxazine-N-oxides resulting
Generation and cycloaddition reactions of 3-substituted-2-nitro-1,3-dienes.
作者:Achille Barco、Simonetta Benetti、Gian P. Pollini、Giampiero Spalluto、Vinicio Zanirato
DOI:10.1016/s0040-4039(00)74370-x
日期:1991.11
Two procedures for the regiospecific preparation of 3-substituted-2-nitro-1,3-dienes have been developed. The cycloaddition chemistry of the in situ generated dienes has been investigated.