Solid-Phase Synthesis of Glycosyl Phosphate Repeating Units via Glycosyl Boranophosphates as Stable Intermediates

Solid-phase synthesis of glycosyl phosphate repeating units was investigated using glycosyl boranophosphates as stable precursors. The stable nature of glycosyl boranophosphate enables the elongation of a saccharide chain without remarkable decomposition. After deprotection of the boranophosphotriester linkages to boranophosphodiesters, the intersugar linkages were converted to the phosphate counterparts quantitatively using an oxaziridine derivative. This method significantly improves the synthesis of oligosaccharides containing glycosyl phosphate units.