Stereoselective fucosylation of Boc-Ser/Thr/Tyr-OMe 2â4 and several saccharide alcohols 5â7 by coupling with 2-pyridyl tri-O-benzyl-1-thio-β-L-fucosyl donor 1b under iodomethane activation procedure results in the formation of α-linked fucosylated amino acid methyl ester building blocks 8â10 and α-linked fucosyl saccharides 11â13, respectively.