Preparative yield of unprotected glycoside Sug-OR calculated on protected precursor of Sug-Cl (n.d.: not determined); /β ratio according to NMR data; series of experiments demonstrated that these conditions are optimal for the reaction in the presence of AgOTf; Recovery of the acceptor in the form LacNAcβ-O(CH2)3NH2 (11) 58%; Recovery of the acceptor in the form LacNAcβ-O(CH2)3NH2 (11) 66%; Reaction did not proceed without AgOTf.