The synthetic routes to ladder polymers that consist of benzenetetrayl subunits with oxo and methylsulfonio linkages are described. As the key intermediate, poly (phenylene oxide) s having pendant methylsulfenyl groups are prepared by copper-catalyzed oxidative polymerization of the corresponding phenols with O2. The oxidation of the polymer with an equimolar amount of H2O2 in the presence of acetic acid effects the high-yielding ...
