SIMPLIFYING OLIGOSACCHARIDE SYNTHESIS - BORONATE DIESTERS AS CLEAVABLE PROTECTING GROUPS

Phenyl boronate diester was used as a cleavable protecting group on th ioglycoside donors. Procedures to glycosylate the polymer linker combi nation MPEG-DOXOH were developed. The boronate diester was readily rem oved and the resulting diols regioselectively glycosylated using silve r triflate promotion of a trichloroacetimidate donor. Subsequent prote cting group manipulations and cleavage from the polymer yielded perace tylated disaccharides in good yields. The whole sequence requires only one chromatography and is therefore much simpler than traditional pro cedures.