Préparation de dérivés de sucres acétyléniques terminaux et d'acides ynuroniques par réaction de <i>Wittig</i>. Note de laboratoire

Abstract

Synthesis of Terminal Acetylenic Sugars Derivatives and Ynuronic Acids Derivatives by Use of a Wittig Reaction The method described for the preparation of terminal acetylenic sugars presents two advantages over earlier procedures: no new asymmetric center is created and the chain can be extended by one or more C‐atoms. The method also allows preparation of ynuronic acids. The aldehydosugars derivatives 1–7 gave in good to excellent yields the corresponding gem ‐dibromoenoses 8–14 from which either the terminal acetylenic sugars derivatives 15–21 or the ynuronic acids 22–24 were easily prepared. A few examples of 1,3‐dipolar cycloadditions (leading to 28–30 ) with these acetylenic sugar derivatives are also described.