Dérivés de désoxy‐hydroxylamino‐sucres et radicaux libres diglycosylnitroxydes correspondants. Communication préliminaire

Abstract

Deoxy‐hydroxylamino‐sugar Derivatives and Corresponding Diglycosylnitroxides Radicals A number of sugar aldonitrones, including C,N ‐diglycosylnitrones, and ketonitrones have been treated with Grignard reagents or cyanide anion leading to the corresponding deoxy‐hydroxylamino‐sugars. On oxidation (air, H 5 IO 6 or PbO 2 ), these compounds gave the corresponding nitroxide radicals whose ESR. spectra are reported. Analogues of disaccharides, in which the interglycosidic O‐bridge is replaced by a hydroxyimino group, have been obtained by reacting a partially blocked sugar bearing a free hemiacetal group either with a deoxy‐hydroxylaminosugar or with hydroxylamine, followed by reaction with an aldehydosugar and a reducing agent (NaBH 4 ). These reactions represents the key synthetic steps for the oligosaccharide‐type synthesis of deoxy‐hydroxyimino‐oligosaccharides. Their oxidation yielded the corresponding nitroxide radicals whose ESR. spectra gave information on the conformation about the ‘interglycosidic’ bridge. This type of compounds should constitute useful spin markers for biological studies.