Disaccharide glycoside, synthesis Helferich

Helferich reported that mercuric cyanide is sometimes superior to silver carbonate as base in the synthesis of glycosides and disaccharides. Thus the condensation of tetra-O-benzoylbromoglucose (1 equiv.) with benzyl alcohol (1 equiv.) in nitro-methane in the presence of mercuric cyanide (1 equiv.) gives tetra-O-benzoylbenzyl-/3-D-glucose in 90% yield. Zorbach used this general procedure, except that 1,2-dichloroethane was used as the solvent, in a successful synthesis of the cardiac-active... 

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