Aldol reaction of beta-C-glycosylic ketones: synthesis of C-(E)-cinnamoyl glycosylic compounds as precursors for new biologically active C-glycosides.

A series of beta-C-glycosylic ketones were prepared starting from d-glucose, d-xylose, d-mannose, and cellobiose. The beta-C-glycosylic ketones on aldol condensation with different aromatic aldehydes in the presence of a suitable organocatalyst led to the formation of respective C-(E)-cinnamoyl glycosides stereoselectively in good yields as precursors for the synthesis of biologically active compounds.