How is 3,3'-Oxydi(1,2-propanediol) (CAS: 59113-36-9) typically synthesized?

3,3'-Oxydi(1,2-propanediol) is typically synthesized via the condensation of 1,2-propanediol using a strong acid catalyst like sulfuric acid. The reaction involves the formation of an ester intermediate followed by hydrolysis to give the bis-ether product. This method provides good selectivity and yields up to 95% of the desired compound. Other methods include using metal catalysts or microwave-assisted techniques to enhance reaction rates and selectivity.