Reactions of diethyl mesyl- or tosyloxyphosphonates with diethyl phosphite and base: a method claimed to yield bisphosphonates

Reactions of diethyl mesyl- or tosyloxyphosphonates with sodium diethyl phosphite in THF lead to the corresponding phosphono phosphates. Reaction of the mesyloxy derivative with diethyl phosphite in pyridine gives the phosphono phosphate as minor product. Neither method yields bisphosphonates.