Five monophosphates of methyl l-glycero-α-d-manno-heptopyranoside: synthesis, hydrolysis and migrations

From suitably protected methyl α-d-mannopyranosides five methyl l-glycero-α-d-manno-heptopyranosides were synthesized by the one-carbon-atom chain elongation at C-6 and converted to five monophosphates (1–5) having the PO(OH)2 group at O-2, -3, -4, -6 and -7. Compounds 1–5 were exposed to acidic and basic hydrolytic conditions used in lipopolysaccharide analysis and the products and their proportion were determined. Under acidic conditions, besides hydrolysis of the glycoside, migrations and hydrolytic cleavage of the phosphate residue were found. Under basic conditions the phosphates were stable.