We prepared 2,2-dibutyl-2-stanna-1,3-dithiacycloalkanes from dibutyltin oxide and alpha, omega-dimercaptoalkanes. Heterocycles with five-, six-, seven-, or nine-ring members were used as bifunctional monomers for polycondensations with aliphatic dicarboxylic acid chlorides. These polycondensations conducted in bulk were highly exothermic and yielded poly(thio ester)s with number average molecular weights (M-n's) in the range of 5000-30,000 Da. These poly(thio ester)s proved to be rapidly crystallizing materials with melting temperatures in the range of 90-150 degrees C. In addition to the success of the new synthetic approach, two interesting and unpredictable results were obtained. All volatile species detectable by matrix assisted laser desorption induced-time of flight (MALDI-TOF) mass spectrometry were cyclic oligo- and poly(thio ester)s. Second, several polyesters showed a reversible first-order change of the crystal modification as identified by differential scanning calorimetry measurements and X-ray scattering with variation of the temperature.