Synthesis and glycosidic reaction of 1,2-anhydromanno, lyxo-, gluco-, and xylofuranose perbenzyl ethers

Stereospecific synthesis of 1,2-anhydromanno-, lyxo-, gluco-, and xylofuranose perbenzyl ethers was successfully achieved via intramolecular S(N)2 reaction of the corresponding C-1 alkoxide with C-2 bearing tosyloxy group. The key intermediates, furanose 2-sulfonates, were prepared from the corresponding 1,2-diols and tosyl chloride under phase transfer conditions in good yields. Condensation of the anhydro sugars with 1,2:3,4-di-O-isopropylidene-alpha-D-galactopyranose or N-benzyloxycarbonyl L-serine methyl ester in the absence of catalyst gave 1,2-trans-linked glycofuranosides in high yield.