SYNTHESIS AND ELABORATION OF MONO- AND OLIGO-SACCHARIDES

This thesis has been addressed towards several issues of synthetic carbohydrate chemistry. Part of the work has focused on original approaches for the functionalization of mono- and oligo-saccharides through the regioselective de-O-benzylation of protected sugars based on the I2/Et3SiH combined system, the chemoselective removal of a range of alkoxycarbonyl groups from carbinols, and the straightforward access to 2-O-deprotected allyl glycosides by BiBr3-promoted activation of peracetylated glycosyl iodides. In the second part of this work, two different sequential one-pot schemes for the rapid assembly of biologically relevant oligosaccharides have been reported. The first strategy allowed the the straightforward synthesis of the antitumor PI-88 pentasaccharide, while the second one afforded oligosaccharides related to HIV gp120.