Cyclization of N-alkylazinium cations with bisnucleophiles. 6. Cycloelimination of tetrahydro-endo-furo[2,3-b]quinoxalines leading to 2,3-disubstituted tetrahydroquinoxalines

The reaction of an N-methylquinoxalinium salt with a -diketone under thermodynamic-control conditions leads to 2,3-disubstituted tetrahydroquinoxaline via cycloelimination of the initially formed tetrahydro-endo-furo[2,3-b]quinoxaline.See [1] for communication 5.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1410–1416, October, 1982.