Polymer-supported C,C-dialkylated malonates were deethoxycarbonylated quantitatively by inorganic salts applied in dipolar aprotic medium. Changes of the reagent excess, temperature, quality of the reagent as well as of the solvent were tested. Effect of the temperature was found as decisive: unusual low (100 degreesC) temperature resulted in complete transformations. The advantages of deethoxycarbonylation in polymer-supported synthesis were evaluated comparing it to the traditional reaction sequence (hydrolysis + decarboxylation). Polymer-supported substrates were directly tested by 112 spectrophotometry. The relatively new field of deethoxycarbonylations was extended to the area of polymer-supported synthesis resulting in a new tool for preparation of polymer-supported esters.(C) 2002 Elsevier Science B.V. All rights reserved.