In the presence of catalytic amounts of Cp*RuCl(cod), the partially intramolecular cyclotrimerizations of various C-alkynylglycosides and C-diynylglycosides proceeded at ambient temperature to afford C-arylglycosides.
A cross-linked nucleoside of the present invention is a compound represented by the formula (I) below. The cross-linked nucleoside of the present invention is usable as a substitute for a phosphorothioate-modified nucleic acid, which has a risk of, for example, accumulation in a specific organ. The cross-linked nucleoside also has excellent industrial productivity.