A fructofuranosyl thioglycoside donor, Et 6-O-acetyl-3-O-benzyl-1,4-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-diyl)-2-thio-b-D-fructofuranoside, designed to yield stereospecifically b-linkages and also to allow subsequent elongation in the 6- and/or 1-positions, was prepd. and used in syntheses of levan and inulin structures. DMTST-promoted glycosylation between fructofuranosyl thioglycoside donor (1.3 mol equiv) and Me b-D-fructofuranoside 6-OH and 1-OH acceptors gave stereospecifically the protected Me levanobioside and inulinobioside in excellent yields (80 and 86%), resp. Protecting group manipulations on these afforded new disaccharide 6'-OH and 1'-OH acceptors, which were coupled again with donor fructofuranosyl thioglycoside donor (1.0 mol equiv) to yield Me levanotrioside and inulinotrioside in high yields, 65 and 67%, resp. These were transformed into new acceptors and also fully deprotected to afford the Me glycosides of levanotriose and inulinotriose, all structures that have earlier not been accessible by chem. synthesis. [on SciFinder (R)]