The title trisaccharide (I) was synthesized from Me 2,3,4-tir-O-benzyl-L-glycero-a-D-manno-heptopyranoside by acetolysis, followed by conversion into Et thioglycoside and also glycosyl bromides, which were both used in glycosylation reactions. In glycosylations using thioglycosides as glycosyl donors, N-iodosuccinimide-silver triflate and dimethyl(methylthio)sulfonium triflate were used as promoters, and in glycosylation with glycosyl bromides silver triflate was used. The protecting groups introduced into intermediates during the synthesis of I were designed to allow later glycosylation at O-3' to give larger oligosaccharide fragments of the Salmonella LPS core region, and also to allow the introduction of phosphate groups at O-4 and O-4', a structural element that is suggested to be present in the Salmonella Ra core. [on SciFinder (R)]