Synthèse de C‐glycosides dérivés du pyrazole et de l'isoxazole. Communication préliminaire

Abstract

Abstract Bromination of 2.3:4.5‐di‐O‐isopropylidene‐ aldehydo ‐ D ‐arabinose p ‐nitrophenyl‐hydrazone affords the corresponding hydrazidic bromide. Similarly, chlorination of 3‐O‐benzyl‐1,2‐O‐isopropylidene α‐ D ‐ xylo ‐pentodialdo‐1,4‐furanose oxime leads to the corresponding hydroxamoyl chloride. These two compounds constitute useful new synthetic intermediates in carbohydrate chemistry. For example, they may be ethynylated, then cyclised respectively to pyrazolyl‐ and isoxazolyl‐C‐glycosides.