Synthesis and behaviour under acidic conditions of 2-deoxy-D-arabino-hexopyranose and 3-deoxy-2-ketoaldonic acids bearing O-phosphono or O-glucosyl substituents at position β to the carbonyl function

Abstract

Methyl 4-O-phosphono- and 4-O-(β-D-glucopyranosyl)-3-deoxy-β-D-erythro-2-hexulopyranosidonic acids, and 3-O-phosphono-, and 3-O-(β-D-glucopyranosyl)-2-deoxy-α-D-arabino-hexopyranoses have been synthesised and their behaviour in acidic media examined. At 100 °C, release of inorganic phosphate from the 4-O-phosphonohexulopyranosidonic acid is faster at pH 3–6 than at pH 0–1 and occurs through an elimination initiated by proton transfer. Phosphate release from the 3-O-phosphono-2-deoxy-hexopyranose occurs by a similar mechanism, but is much slower. Treatment at 100 °C with acetic acid of pH 3.4 causes release of glucose from the 4-O-glucosylated-3-deoxy-hexulopyranosidonic acid but not from the 3-O-glucosylated-2-deoxy-hexopyranose.