The electrochemical oxidation of a cyclic peralkylsilane derivative, [(n-Pr)(2)Si](5) (I), in dichloromethane in the presence of ClO4- or AcO- salts, leads to both oxygen insertion and ring-opening processes, to form mainly cyclic and linear siloxanes. The latter contain various groups at their terminal positions : OH, AcO, CH2CN or n-propyl.