Reactions of Nucleophiles with Reactive Intermediates in the 3,4,6-Tri-O-benzyl-D-glucal-TfOH-n-Bu₄NI Reaction System

The unique reactive intermediate formed in the 3,4,6-tri-O-benzyl-D-glucal- TfOH (triflic acid)-n-Bu₄NI reaction system (in dichloromethane) reacted with nucleophiles in a regio- and stereoselective manner. These selectivities resulted in hitherto unknown compounds, such as benzyl 4,6-di-O-benzyl-2,3-dideoxy-3-iodo-α-glucopyranoside, which was obtained in the presence of an iodide ion as a nucleophile. The corresponding 2-deoxy α-glycosides were obtained exclusively in the corresponding reaction with hydroxylic nucleophiles.