PRESPACER GLYCOSIDES IN GLYCOCONJUGATE CHEMISTRY - DIBROMOISOBUTYL GLYCOSIDES FOR THE SYNTHESIS OF NEOGLYCOLIPIDS, NEOGLYCOPROTEINS, NEOGLYCOPARTICLES, AND SOLUBLE GLYCOSIDES

3-Bromo-2-(bromomethyl)propyl (dibromoisobutyl or DIB) mono- to tetrasaccharide glycosides were prepared in moderate to high yields by treatment of the corresponding 1-0-acetyl saccharides with 3-bromo-2-(bromo-methyl)propanol (DIBOL) and boron trifluoride etherate. Treatment of the DIB glycosides with alkyl- and cu-methoxycarbonylalkyl thiols gave the corresponding bis-sulfide glycolipids and spacer arm sugars, respectively. Oxidation of the sulfides with m-chloroperbenzoic acid gave the corresponding bis-sulfones. Treatment of the DIB glycosides with tetrabutylammonium fluoride gave the corresponding allylic bromide glycosides, and addition of thiols gave the allylic sulfides. Prolonged fluoride treatment gave the allylic fluorides. Hydrogenation of DIB glycosides under basic conditions gave the corresponding isobutyl glycosides. Spacer arm and allylic bromide glycosides were coupled to bovine serum albumin and derivatized silica gel, thereby providing artificial glycoprothins and glycoparticles. © 1990, American Chemical Society. All rights reserved.