Ferrier Reaction: The first synthesis of 2,3-unsaturated seleno-glycosides by using alkyl(aryl) hydroselenides as the nucleophile and Hf(OTf)4 as the catalyst.

Graphical abstract Highlights • 2,3-Unsatureted seleno-glycosides was synthesized first time with Ferrier Reaction. • Hf(OTf) 4 was used as catalyst for the preparation of 2,3-unsatureted seleno-glycosides. • Promoted by Hf(OTf) 4 , (RSe) 2 could be used as nucleophile source under reductive condition. Abstract By using Hf(OTf) 4 as the catalyst, a series of 2,3-unsaturated- Se -glucosides have been synthesized for the first time from tri- O -acetyl- d -glucal, 2,4,6-tri- O -benzyl- d -glucal, 3,4-di- O -acetyl- l -rhamnal and ((2 R ,3 S)-3-acetoxy-2,3-dihydrofuran-2-yl) methyl acetate with PhSeH or alkyl(aryl) hydroselenides as the nucleophile in good yield and high anomeric selectivity. [ABSTRACT FROM AUTHOR]