Despite the difficulty of direct β-furanosylation with d-fructose, the synthesis of β-d- fructofuranosyl α-d-glucopyranoside,(+)-sucrose 1, has been achieved stepwise, via β- selective d-psicofuranosylation followed by stereo inversion of a hydroxy group at the C-3 position on the furanose ring. d-Psicofuranosyl donor 10 was prepared in eight steps from d- ribose monoacetonide 3 in excellent yield.
