A one-pot strategy for synthesis of 5-O-(alpha-D-arabinofuranosyl)-6-O-(beta-D-galactofuranosyl)-D-galactofuranose present in motif E of the Mycobacterium tuberculosis cell wall.

5-O-(Alpha-D-arabinofuranosyl)-6-O-(beta-D-galactofuranosyl)-D-galactofuranose 6 present in motif E of the Macobacterium tuberculosis cell wall has been regio- and stereospecifically synthesized using 3-O-benzoyl-1,2-O-isopropylidine-alpha-D-galactofuranose (10) as the glycosyl acceptor by the trichloroacetamidate method in a one-pot manner. The diol glycosyl acceptor 10 was smoothly derived from 1,2:5,6-di-O-isopropylidene-alpha-D-galactofuranose (8) by 3-O-benzoylation and then selective 5,6-O-deacetonation. The preparation of 8 was greatly improved by increasing the ratio of DMF to acetone and using a solid-supported catalyst.