A versatile and convenient route to ketone C-pyranosides and ketone C-furanosides from unprotected sugars

Both ketone C-pyranosides (in up to 97% yields) and C-furanosides (in 83–97% yields) could be prepared, respectively, from the condensations of pentane-2,4-dione and various unprotected sugars in sodium carbonate aqueous media by adjusting the reaction conditions.