Cyclization of N-alkylazinium cations with bifunctional nucleophiles. 16. σ-adducts of quinoxalinium salts with amines,alcohols, and enolates and their role in cyclizations with β-dicarbonyl compounds

In the reaction of N-methylquinoxalinium iodide with acetylacetone at –30 °C, the formation of 3-acetyl-2,4-dimethyl-3a,4,9,9a-tetrahydrofuro2,3-b]quinoxaline has been recorded by ¹H NMR spectroscopy, this being a regioisomer of the 3-acetyl-2,9-dimethyl-3a,4,9,9a-tetrahydro2,3-b]quinoxaline formed in this reaction at temperatures above –10 °C. -Adducts of the N-methylquinoxalinium cation with alcohols, amines, and -diketones have also been identified, and their role in cyclizations leading to the annelation of a furan ring is discussed.For Communication 15, see 1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 669–677, May, 1985.