InCl3-induced C-glycosylation of per-O-acetylglycals with allyltrimethylsilane

InCl3 has been used for the first time as a mediator for the C-glycosylation of per-O-acetylglycals with allyltrimethylsilane, and the reactions proceeded to give products in good-to-excellent yield and in high diastereoselectivity. The 1,5-anti diastereoselectivity in the allylation of 3,4,6-tri-O-acetyl-1,5-anhydro-2-deoxy-d-arabino-hex-1-enitol and 3,4-di-O-acetyl-1,5-anhydro-2,6-dideoxy-l-arabino-hex-1-enitol and the 1,4-anti diastereoselectivity with 3,4-di-O-acetyl-1,5-anhydro-2-deoxy-d-erythro-pent-1-enitol are in the range 80–90%, whereas 3,4,6-tri-O-acetyl-1,5-anhydro-2-deoxy-d-lyxo-hex-1-enitol furnished exclusively the corresponding C-α-d-galactopyranosyl compound.