“…A two-stage mechanism for the Diorganyltelluronium ylides [ 187,25 1,2521 and diorganyltellurimides [253,254] react with protonic acids (molar ratio 1 : 2) with cleavage of Te=C and Te=N bonds, respectively, forming a-telluranes R2TeX2 in nearly quantitative yields (Scheme 11 I). SCHEME 11 1 n-Telluranes of all types react easily with carboxylic acid anhydrides to give diorganyl tellurium dicarboxylates 64.…”