Synthesis of Blocked Sugars Bearing a Terminal 1-Cyanovinyl Group

Abstract

A series of blocked sugar aldehydes treated with the conjugate base of nitromethane afforded the expected nitrosugars 1–7, whose configuration at the new asymmetric centre was assigned by CD. Nitroenoses 8–14, obtained from the corresponding saturated β-hydroxy nitrosugars, reacted with potassium cyanide, afforded the terminal 1-cyanovinyl sugar derivatives 15–23. Another route to 1-cyanovinylic sugars bearing a free hydroxy group (24 and 25) consisted in reacting aldehydo sugars with the conjugate base of acrylonitrile. The 1-cyanovinyl sugars are soft electrophiles which react with hydroxylamines to give the product of a conjugate addition (27 and 28). The interest of these compounds resides in their often selective toxicity towards cells, viruses or bacteria.