Syntheses of 2,6-anhydroaldonic acids from the corresponding anhydrodeoxynitroalditols (glycopyranosylnitromethanes) and their conversion into methyl esters, amides, and alditols

2,6-Anhydroaldonic acids were obtained by oxidation of the corresponding anhydrodeoxynitroalditols (glycopyranosylnitromethanes) with hydrogen peroxide in alkaline solution. Purification was achieved via the methyl anhydroaldonates. The syntheses of five 2,6-anhydrohexonic and eight 2,6-anhydroheptonic acids were accomplished in yields of 44-81%. All corresponding unprotected and acetylated methyl 2,6-anhydroaldonates were characterised. Ammonolysis of the former afforded the corresponding amides in quantitative yields; reduction with sodium borohydride gave the analogous anhydroalditols. (C) 1998 Elsevier Science Ltd. All rights reserved.