Neighboring-group participation in benzylidene acetal ring-opening of a 2-cyano-2-deoxypyranoside derivative by diethylaluminum cyanide

Abstract

The oxirane ring-opening of an anhydro sugar with diethylaluminum cyanide (Et 2AlCN) is a direct approach for obtaining a cyano derivative. Methyl 2,3-anhydro-4,6- O-benzylidene-α- d-allopyranoside showed anomalous chemical behavior when treated with Et 2AlCN. The reaction afforded the corresponding β-cyanohydrin as the minor component from a mixture of compounds resulting from the benzylidene acetal ring-opening caused by the attack of ethyl or cyano groups.