diethylzinc and diphenylzinc in the presence of CF3COOH gave the corresponding alky and aryl C-pyranosides via a Ferrierrearrangement in excellent yields. Use of the organozinc species, CF3CO2ZnPh, reacted with high stereoselectivity to give the phenyl C-glycosides. Arylzinc chlorides could also be successfully applied to this reaction in the presence of BF3.OEt2.