H 65 Highly diastereoselective 1,3-dipolar cycloaddition of nonstabilized azomethine ylides to 3-nitro-2-trihalomethyl-2H-chromenes: synthesis of 1-benzopyrano[3,4-c]pyrrolidines [Electronic resource] / V. Yu. Korotaev, A. Yu. Barkov, V. S. Moshkin, E. G. Matochkina, M. I. Kodess, V. Ya. Sosnovskikh // Tetrahedron. - 2013. - Vol.69, №40. - P8602-8608. - Bibliogr. : p. 8608 (13 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 3-NITRO-2H-CHROMENES -- NONSTABILIZED AZOMETHINE YLIDES -- 1,3-DIPOLAR CYCLOADDITION Аннотация: Reactions of 3-nitro-2-trifluoro(trichloro)methyl-2H-chromenes, including 2-unsubstituted derivatives, with N-alkyl-α-amino acids (sarcosine, proline) and paraformaldehyde proceed diastereoselectively to give 1-benzopyrano[3,4-c]pyrrolidines in good yields as a result of a 1,3-dipolar cycloaddition of the intermediate nonstabilized azomethine ylide at the Δ3-bond of the chromene system \\\\expert2\\NBO\\Tetrahedron\\2013, v. 69, p. 8602.pdf |