Summary: la-Monophosphate(2)) 4'-monophosphate(3)) and lo, 4'-diphosphate(4) of 6-0-(2- deoxy-2-tetradecanoylamino-6-O-tetradecanoyl-~-D-glucopyranosyl)-~-deoxy-2- tetradecanoylamino-3, 4-di-O-tetradecanoyl-D-glucopyranose were prepared in order to elucidate the role of phosphate moieties in endotoxic activity of lipid A.