Efficient one-pot syntheses of α-d-arabinofuranosyl tri- and tetrasaccharides present in cell wall polysaccharide of Mycobacterium tuberculosis

Two α-d-arabinofuranosyl oligosaccharides (2 and 3) found as constituent parts of the polysaccharide portion from the cell wall of Mycobacterium tuberculosis have been efficiently synthesized via a one-pot glycosylation procedure in which a key step is the chemoselective activation between d-arabinofuranosyl trichloroacetimidate donor 4 and partially protected aryl thioglycosides 5 or 7, respectively.