For the synthesis of polyethers with a variety of keto side chains in a one-step reaction, the three-component polycondensation of dialdehydes, diol disilyl ethers, and silyl enol ethers of ketones was investigated. The method of monomer addition strongly affected the molecular weight of polymers and was optimized to yield high molecular weight polymers by model reactions. A variety of dialdehydes, diol disilyl ethers, and silyl enol ethers were polymerized in the presence of a catalytic amount of triphenylmethyl (trityl) perchlorate in CH2Cl2 at -78 degrees C according to the method of monomer addition. This polymer synthesis was unusual in that it concurrently constructed both the polyether backbone and the keto side chains from three starting compounds.