α-Selectivity and glycal formation are temperature dependent in glycosylation with sialic acid. Synthesis of a Neu5Acα(2-6)Gal thioglycoside building block

Article abstract of DOI:10.1016/0040-4039(91)80132-P

The glycosylation with the N-acetylneuraminic acid (Neu5Ac) donor 1 of the 6-OH position of D-galactose in various nitriles promoted by methylsulfenyl triflate at different temperatures is reported. The proportion of α-sialoside increased and glycal 5 decreased at lower temperatures. A short route to a Neu5Acα(2-6)Gal thioglycoside building block is also described.