Improved synthesis of the Kijanimicin oligodeoxytetrasaccharide

By sequential synthesis the four 2,6-dideoxy saccharide moieties of the kijanimicin tetrasaccharide could be stereoselectively assembled. For formation of all required 2-deoxy α-glycoside linkages various S-(hexopyranosyl)-phosphorodithioates as donor structures could be convincingly employed. The terminal 2-deoxy β-glycoside linkage was stereoselectively formed following the dibromomethyl methyl ether approach. The target octadeoxy-tetrasaccha-ride could be obtained via nine subsequent steps in 5% overall yield.