Glycoside synthesis remote activation concept

Glycoside Synthesis Based on the Remote Activation Concept An Overview... 

B. Lou, G. V. Reddy, H. Wang, and S. Hanessian, Glycoside and oligosaccharide synthesis with unprotected glycosyl donors based on the remote activation concept, in S. Hanessian, (Ed.), Preparative Carbohydrate Chemistry, Marcel Dekker, Inc., New York, 1997, p. 389. 

Hanessian, S. Glycoside synthesis based on the remote activation concept an overview. In Preparative Carbohydrate Chemistry. Hanessian, S. (ed.) Marcel Dekker New York, 1997, pp. 381-388. 

In spite of the successful implementation of the concept of remote activation of an anomeric 2-pyridylthio group, there emerged various issues and questions. The absence of self-condensation products could be ascribed to the use of excess acceptor in all cases, and possibly to the coordination of the mercuric salt to the free hydroxy groups of the donor, thereby diminishing their reactivity. However, the necessity to use an excess of acceptor (> 5 eq), the formation of anomeric mixtures of glycosides, and the use of a mercuric salt, limited the generality of this method of glycoside synthesis. 

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