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

Abstract

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.

Keywords:

• Carbohydrates
• Glucal
• Reactive intermediates
• Nucleophiles
• Iodosugars
• 2‐deoxyglycopyranosides

Acknowledgment

Useful discussions with Professor Richard R. Schmidt of Konstanz University, Germany, are gratefully acknowledged.