Dérivés d'énose‐ et d'ynosephosphonates et composés voisins. Communication préliminaire

Abstract

Derivatives of enose‐ and ynosephosphonates and related compounds. Preliminary communication The gem ‐dibromo terminal enoses 1 and 7 are convenient sources of glycosylacetylenes which upon reaction with phosphorus electrophiles gave the phosphorusbearing acetylenic sugars 4, 5 and 8 . Compounds 5 and 8 underwent cycloaddition reactions leading to isoxazolyl‐ C ‐glycosides 6 and 9 respectively. The nitroolefinic sugar derivative 11 gave upon bromination‐dehydrobromination the first example of a new kind of potentially useful synthetic intermediates, the gem ‐bromonitroenose 12 . The enosephosphonate 13 was also prepared from 11 . The diglycosylhydroxylamine 18 represents another type of phosphorus‐bearing acetylenic sugar derivative. Some 1 H‐ and 13 C‐NMR. data relative to the new types of phosphorus‐containing sugar derivatives synthesized are given.