Reactions of N-substituted allylacetic acid amides with selenium and tellurium tetrahalides

The addition of selenium tetrabromide to the olefinic bond of N-substituted allylacetic acid amides (reagent molar ratio 21) proceeds counter to Markownikoff's rule with the formation of tetrahydrofuran derivatives. The addition of tellurium tetrahalides under the same conditions (reagent molar ratio 11) proceeds in accordance with Markownikoff's rule with the formation of tetrahydropyran derivatives.Communication 10 in the series Electrophilic reactions of halides of elements of the sixth group; see [1] for Communication 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 743–745, June, 1989.