2,2:3,3-Bis(4'-hydroxymethylethylenedioxy)-1,7,7-trimethylbicyclo[2.2.1]heptane, abbreviated as CaG, is a compound obtained by transforming a ketone group to a ketal group with camphorquinone and glycerol. The CaG diol has a complex and rigid structure and two primary hydroxyl groups. A polyester series was synthesized with the CaG diol, ethylene glycol, and dimethyl terephthalate. The polyesters exhibited adequate thermal stability up to nearly 330 °C and had a high Tg, which steadily increased from 78 to 129 °C as the content of CaG increased. A high proportion of the CaG moiety led to an amorphous region that is susceptible to hydrolysis and promoted degradation of the polyester in acidic conditions. Depending on the proportion of CaG in the polymer, the hydrolytic degradation of the polyesters was adjustable.