C 98 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 [Electronic resource] / V. N. Charushin, M. G. Ponizovskii, O. N. Chupakhin, E. O. Sidorov, I. M. Sosonkin // Chemistry of Heterocyclic Compounds. - 1985. - Vol. 21, № 5. - С. 564-572. - Bibliogr. : p. 571-572 (16 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ACETYLACETONE -- 1H NMR SPECTROSCOPY -- N-METHYLQUINOXALINIUM CATION Аннотация: In the reaction of N-methylquinoxalinium iodide with acetylacetone at −30 °C, the formation of 3-acetyl-2,4-dimethyl-3a,4,9,9a-tetrahydrofuro[2,3-b]quinoxaline has been recorded by 1H NMR spectroscopy, this being a regioisomer of the 3-acetyl-2,9-dimethyl-3a,4,9,9a-tetrahydro[2,3-b]quinoxaline formed in this reaction at temperatures above −10 °C. σ-Adducts of the N-methylquinoxalinium cation with alcohols, amines, and β-diketones have also been identified, and their role in cyclizations leading to the annelation of a furan ring is discussed. \\\\expert2\\nbo\\Chemistry of Heterocyclic Compounds\\1985, v.21, N 5, p. 564.pdf |