How is Disodium 5'-O-({[(phosphonooxy)phosphinato]oxy}phosphinato)guanosine (CAS: 56001-37-7) typically synthesized?

Disodium 5'-O-({[(phosphonooxy)phosphinato]oxy}phosphinato)guanosine (CAS: 56001-37-7) is synthesized using a multi-step process involving the condensation of guanosine with a phosphonate, followed by a series of phosphonate esterification reactions. Commonly used catalysts include titanium(IV) isopropoxide and other organometallic compounds. The reaction yields around 85% of the desired product. The process is carried out in a controlled environment to ensure high purity and yield.