The reaction of readily available dialkyltrimethylsilylsilyi phosphite
s (RO)(2)POSiMe(3)5 with sulfur dichloride leads to tetra-alkyl sym-mo
nothio-pyrophosphates (RO)(2)P(O)SP(O)(OR)(2) 1 in high yield. The met
hod is suitable for the synthesis of tetra t-butyl thiopyrophosphate 1
d.