H/D isotope exchange in 9-R-sym-octahydro-10-oxonia(chalcogenonia)anthracene perchlorates

The method of controlled H/D isotope exchange in acid media has been used to study the effect of the heteroatom and the substituents in 9-R-sym-octahydro-10-oxonia(chalcogenonia)anthracene perchlorates on the mobility of hydrogen atoms in the -methylene units of alicyclic rings condensed with heteroaromatic rings. It has been established that in a group of aryl-substituted salts the mobility of the hydrogen atoms increases in the series S⁺++, which corresponds to a decrease in thermodynamic stability of the chalcogenopyrylium cations. In a group of unsubstituted salts (R=H) the order of reactivity of the methylene groups is O⁺++ and corresponds to the increasing orbital electrophilicity and complexing ability of these cations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 463–467, April, 1993.