From Other Tellurium Tetraalkoxides

Tellurium tetraisopropoxide reacted with an excess of alkanols in refluxing benzene to produce tellurium tetraalkoxides and isopropanol. Ethanol or methanol reacted at 20° without benzene as solvent.  

Tellurium Tetrabutoxide 10 g (135 mmol) of butanol are added to 2.71 g (7.4 mmol) of tellurium tetraisopropoxide and the mixture is diluted with benzene. After the exothermic reaction has subsided, the mixture is heated under reflux for 2 h and then the isopropanol/benzene azeotrope is distilled from the mixture at 72°. Excess butanol and benzene are distilled off, the residue is dried under reduced pressure at 20°, and the resultant colorless liquid is distilled yield 2.9 g (92%) b.p. 150 /0.8 torr. 

When tellurium tetraisopropoxide was treated with an equimolar amount of a diol, two isopropoxide groups were replaced. Reactions of two moles of a diol per mole of tellurium tetraisopropoxide, resulted in replacement of all four isopropoxide groups.  

2-Diisopropoxy-4,5-dihydro-l,3,2-dioxatellnrole7 To a flask fitted with a reflux condenser and protected from moisture is added a solution of 2.0 g (5.5 mmol) of tellurium tetraisopropoxide in anhydrous benzene, 0.34 g (5.5 mmol) of glycol are added, and the mixture is heated under reflux for 1 h. The isopropanol/benzene azeotrope is slowly distilled at 72°, excess benzene is distilled, and the residue is dried under reduced pressure. The remaining white solid product is insoluble in benzene and cannot be sublimed without decomposition to 1,4,6,9-tetraoxa-5-telluraspiro[4.4 nonane yield 1.63 g (82%). 

Similarly prepared were the following tellurium diisopropoxide a,(o-polymethylene dioxides . 

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