STABLE CARBONIUM IONS .62. HALONIUM ION FORMATION VIA NEIGHBORING HALOGEN PARTICIPATION - ETHYLENEHALONIUM PROPYLENEHALONIUM AND 1,2-DIMETHYLETHYLENEHALONIUM IONS

Bridged halonium ions were observed to arise on ionization of 1,2-dihaloethanes, 1,2-dihalopropanes, and 2,3-dihalobutanes when the participating atom is iodine or bromine. Starting from erythro- or threo-2-bromo-3-fluorobutane, the same mixture of cis- and trans-dimethylethylenebromonium ions was obtained, but from the corresponding iodides, stereospecific formation of the trans- and cis-1,2-dimethylethyleneiodonium ions, respectively, was observed. These latter ions were stereospecifically solvolyzed in methanol to the reported methyl ether. © 1968, American Chemical Society. All rights reserved.