yield the pentasaccharide derivative 17 the chloroacetyl group of which was removed to give in 71 yield intermediate 18 scheme iv compounds 13 and 18 are key intermediates for obtaining the desired inhibitors 14 16 and 19 thus for the production of compound 14 the partially protected 13 was subjected to complete removal of the blocking groups in three successive steps see example 9 whereas for obtaining the sialylated compound 16 the same intermediate 13 was allowed to react with known sialyl donor 4 to give in 47 yield the hexasacchalide derivative 15 scheme iii the u03b1 configuration for the sialic acid residue was confirmed by the 1 h nmr of 15 which exhibited a double doublet at u03b42 67 j 4 6 hz attributable to h 3e of this residue the conversion of 15 into the target compound 16 scheme iii was performed in four successive steps 1 lithium iodide pyridine methyl ester to free acid 2 methanol hydrazine hydrate removal of the phthalimido group 3 acetic anhydride methanol dichloromethane n acetylation and 4 methanolic sodium methoxide o deacetylation the 1 h and 13 c nmr spectra of 16 were in accord with the structure assigned see examples for the production of the target compound.