Diacetoxylation of nonconjugated dienes with TeO₂ and the isolation of intermediate organotellurium compounds

Tellurium(IV) oxide (TeO₂) reacts with nonconjugated dienes in acetic acid at reflux temperature in the presence of lithium halide or iodine to give the corresponding vic-diacetates in moderate yields. When the reaction is carried out at 80°C and the reaction mixture is then reduced with aqueous sodium thiosulfate, bis(β-acetoxyalkyl)ditellurides are isolated as main products. Treatment of the ditellurides with refluxing acetic acid affords the corresponding vic-diacetates in good yields. The expected tellurium containing heterocyclic compounds, such as telluracyclopentanes and telluracyclohexanes, are not formed and/or isolated under the conditions employed. When 4-vinylcyclohexene and limonene are used as dienes in the diacetoxylation reaction, aromatic compounds due to the dehydrogenation of cyclohexene ring are also produced in moderate yields.