Novel six-membered bis- and tris-(cyclic carbonate)s that are useful as cross-linking agents in the synthesis of structurally stable yet biodegradable polycarbonates and polyesters have been synthesized in good to moderate yield (85-45%). Cross-linked aliphatic polycarbonates, and polyesters were prepared by copolymerization of the bis-cyclic carbonate (3f) with trimethylene carbonate, and E-caprolactone. The polymers swelled in a wide variety of organic solvents, including CHCl3, CH2Cl2, ethyl acetate, acetone, DMSO, and DMF but not in protic polar solvents, such as methanol, ethanol, and water. Swelling ratios of trimethylene carbonate/3f and epsilon-caprolactone/3f networks at different feed ratios were investigated in dichloromethane. The glass transition temperature of the TMC/3f networks increased with increasing cross-link density.