Synthesis of a beta 1,2-mannopyranosyl tetrasaccharide found in the phosphomannan antigen of Candida albicans

[GRAPHICS] The synthesis of a portion of the challenging beta 1,2-mannosyl polymer fou nd in the cell walls of Candida albicans was undertaken to develop a conjug ate vaccine against C. albicans and to facilitate NMR conformational studie s of this unique polysaccharide. The novel approach to the synthesis of tet rasaccharide 1 employed the modified ulosyl bromide 11 as the glycosyl dono r which provided high diastereoselectivity. A participating solvent as well as p-chlorobenzyl protection facilitated the new approach.