Catalytic and highly stereoselective β-mannopyranosylation using a 2,6-lactone-bridged mannopyranosyl ortho-hexynylbenzoate as donor

An efficient and catalytic protocol for highly stereoselective construction of β-mannopyranosylation has been developed. Glycosylation of 2,6-lactone-bridged mannopyranosyl ortho-hexynylbenzoate with various acceptors proceeded smoothly in the presence of 5% Hg(II) at room temperature, resulting in the corresponding β-mannosides in high yield and exclusive β-stereoselectivity. Glycosylation of 2,6-lactone-bridged mannopyranosyl ortho-hexynylbenzoate with various acceptors proceeded smoothly in the presence of 5% Hg(II) at room temperature, resulting in the corresponding β-mannosides in high yield and exclusive β-stereoselectivity. [Display omitted]