Bromoacetals to Carboxylic Acid Esters

Oxidation of the ethylene acetals of 3-aryl-3-oxo-2-propyl phenyl telluriums, which were prepared from the acetals of 3-aryl-3-oxo-2-bromopropane and arenetellurolates, with 3-chloroperoxybenzoic acid in methanol at 20° produced hydroxyethyl 2-arylpropanoates. Tellurones were postulated as intermediates that experienced a 1,2-aryl shift and the elimination of an aryltelluro moiety. 

Diorgano tellurium derivatives were used as catalysts to effect the following transformations  

Diisobutyl tellurium induces the reaction of tosyl azide with aldehydes to form tosylimines. Ketones do not react under these conditions.  

Dibutyl tellurium induced cyclopropanation of a,j8-unsaturated esters, ketones, and nitriles with dibromomalonic acid derivatives. Bis[4-methoxyphenyl] tellurium hardly promoted these reaction even at 150° 

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