Copolymerization of 5,5-bis(hydroxymethyl)-2-phenyl-1,3-dioxane with dimethyl terephthalate and either ethylene glycol or 1,4-butanediol affords polyesters with pendant ketals. Acid-promoted debenzalation provides 2,2-bis(hydroxymethyl)propane-1,3-diyl structural units. Thermal transesterification to afford rigid, adhesive thermosets is controlled by the composition of the copolymer and curing conditions (temperature and time).