Synthesis of 2-deoxy-4-O-α- and -β-d-mannopyransyl-l-erythro-pentonic acids

Abstract

The title compounds, required for the identification of structural features of the Bordetella pertussis endotoxin, have been synthesised by condensation of benzyl 3-O-benzyl-2-deoxy-β-l-erythro-pentopyranoside with 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl bromide and with 4,6-di-O-acetyl-2,3-O-carbonyl-α-d-mannopyranosyl bromide, respectively, thus affording the fully protected α- and β-linked disaccharides 7 and 12. Hypoiodite oxidation of the reducing disaccharides 9 and 14, obtained by conventional deprotection of 7 and 12, yielded the title compounds.