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 correspondi ng anhydrodeoxynitroalditols (glycopyranosylnitromethanes) with hydrog en peroxide in alkaline solution. Purification was achieved via the me thyl anhydroaldonates. The syntheses of five 2,6-anhydrohexonic and ei ght 2,6-anhydroheptonic acids were accomplished in yields of 44-81%. A ll corresponding unprotected and acetylated methyl 2,6-anhydroaldonate s were characterised. Ammonolysis of the former afforded the correspon ding amides in quantitative yields; reduction with sodium borohydride gave the analogous anhydroalditols. (C) 1998 Elsevier Science Ltd. All rights reserved.