Cleavage of the C–C linkage between the sugar and the aglycon in C-glycosylphloroacetophenone, and the NMR spectral characteristics of the resulting di- C-glycosyl compound

Abstract

The treatment of unprotected mono- C-β- d-glucopyranosylphloroacetophenone with a cation-exchange resin in anhydrous acetonitrile afforded both a phloroacetophenone and a di- C-β- d-glucopyranosylphloroacetophenone. Treatment of an unprotected mono- C-(2-deoxy-β- d- arabino-hexopyranosyl)phloroacetophenone (mono- C-2-deoxy-β- d-glucopyranosylphloroacetophenone) also afforded both the aglycon and di- C-(2-deoxy-β- d- arabino-hexopyranosyl)phloroacetophenone. The reaction mixtures were acetylated, and the structures of the isolated products were determined by NMR spectroscopy. This is the first demonstration of the formation of a di- C-glycosyl compound during the chemical cleavage of the C–C linkage between the sugar and the aglycon in an aryl C-glycosyl derivative.