Reaction with 5,5-Dimethyl-l,3-dioxocyclohexane

Telluraxanthene 7h,7h-dichloride condensed with 5,5-dimethyl-l,3-dioxocyclohexane to form an ylideh 

4-Dimethyl-2,6-dioxocyclohexylidene)-telluraxantheneh 7.28 g (20 mmol) of telluraxanthene Te,Te-dichloride and 2.8 g (20 mmol) of 5,5-dimethyl-l,3-dioxocyclohexane are dissolved in 60 ml of benzene, the solution is stirred at 60-70°, and 1 ml (5 A g 50 mmol) of triethylamine are added. The solution is heated and stirred for a further 20 min, filtered hot, and the solvent is distilled from the filtrate. The colorless crystals are recrystallized from benzene/pctroleum ether yield 8.6 g (100%) m.p. 156°. 

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Diaryl tellurium dihalides condense with 5,5-dimethyl-l, 3-dioxocyclohexane in benzene in the presence of triethylamine to give cyclohexylidene diaryl tellurium compounds. Whether a reaction occurs at 20° or requires elevated temperatures is determined by the substituents on the aryl groups. Dimethyl tellurium dichloride and aryl methyl tellurium dichlorides react at 20°. 

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