Studies on Organophosphorus Compounds, 53: A New Procedure for the Synthesis of 1-Alkyl or 1-Aryl-1-hydroxy-2-nitroethylphoshonates under PTC Conditions
A series of dialkyl 1-alkyl- or 1-aryl-1-hydroxy-2-nitroethyl-phosphonates and 1-hydroxy-1-(nitromethyl)alkylphosphonates was prepared by nucleophilic addition of nitromethane to dialkyl acylphosphonates in the presence of potassium carbonate and tetrabutylammonium bromide.
Herein, a synthesis of 2-phosphonodihydrofurans and 2-phosphonodihydropyrroles via 5-endo cyclization of O-and N-propargylated compounds is described. The reaction is promoted by potassiumtert-butoxide and allows a fast access to interesting heterocycles which were easily converted into 2-arylated pyrroles under acidic conditions.