The title trisaccharide glycoside, which is related to part of the core region of the lipopolysaccharide from Salmonella, and the disaccharide glycosides Me 3-O-a-D-glucopyranosyl-L-glycero-a-D-manno-heptopyranoside and Me 7-O-L-glycero-a-D-manno-heptopyranosyl-L-glycero-a-D-manno-heptopyranoside have been synthesized. Me 2,3,4-tri-O-benzyl-L-glycero-a-D-manno-heptopyranoside, obtained via a one-carbon elongation at C-6 of Me 2,3,4-tri-O-benzyl-a-D-manno-hexodialdo-1,5-pyranoside, was used as precursor both for the heptosyl donor and acceptor. [on SciFinder (R)]