M. Ludewig et al., SYNTHESIS OF SYMMETRICAL DIFUCOPYRANOSE DIANHYDRIDES, Journal of the Chemical Society. Perkin transactions. I, (11), 1998, pp. 1751-1752
By activation of methyl 3,4-O-isopropylidene-1-methyl thio-beta-L-fuco
pyranoside (1) with copper bromide-tetrabutylammonium bromide, bis(3,4
-O-isopropylidenea-alpha-L-fucopyranose)-1 ,2': 1',2-dianhydride (2) w
ith almost C-2-symmetry was obtained. Starting with the monosaccharide
precursors 3 and 4 a corresponding activation led to the disaccharide
derivative 5 which in turn was converted into the mixed D,L-dianhydri
de 7 employing an intramolecular imidate glycosylation.