Synthesis of 3-S- and 3-Se-glycals by using R-S-S-R and R-Se-Se-R as the nucleophile precursors promoted by Hf(OTf)4 and the temperature-dependent formation of the above-mentioned 3-S- and 3-Se products

By using Hf(OTf)(4) as the catalyst, under certain conditions, reaction of tri-O-acetyl-D-glucal and ((2R,3S)-3-acetoxy-2,3-dihydrofuran-2-yl)methyl acetate with alkyl(aryl) bisulfide/alkyl(aryl) biselenide as nucleophile precursor leads to temperature-dependent formation of C-1-S/Se and C-3-S/Se product. A temperature-dependent profile of the yield of these two products is given. (C) 2020 Elsevier Ltd. All rights reserved.