U 50 Uncatalyzed reactions of alfa-(trihaloethylidene)nitroalkanes with push-pull enamines: a new type of ring-ring tautomerism in cyclobutane derivatives and the dramatic effect of the trihalomethyl group on the reaction pathway [Text] / V. Yu. Korotaev, A. Yu. Barkov, P. A. Slepukhin, M. I. Kodess, V. Ya. Sosnovskikh // Tetrahedron Letters. - 2011. - In Press, Accepted Manuscript, 30 august 2011. - P1-15. - Bibliogr. : p. 10-12 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A new type of ring-ring isomerism, which consists of the reversible transformation of cyclobutane derivatives into substituted 1,2-oxazine N-oxides was found and studied by NMR spectroscopy and X-ray diffraction analysis. The starting materials were prepared by the stereoselective reaction of ?-(trifluoroethylidene)nitroalkanes, which react with ethyl ?-morpholino- and ?-piperidinocrotonates at the more nucleophilic ?-position, whereas the reaction of ?-(trichloroethylidene)nitroalkanes proceeds at the ?-methyl group to give the corresponding linear products \\\\Expert2\\nbo\\Tetrahedron Letters\\2011, In Press, Acc. Man. 30 aug.pdf |