Synthesis of Fluorinated Carbohydrates

The similarities in bond length and polarization between C-F and C-OH, as well as the altered hydrogen-bonding properties present in carbohydrates bearing a fluorine atom in place of an hydroxyl group can be exploited in place of an hydroxyl group can be exploited in biochemical investigations (enzyme-carbohydrate interactions, Lectin-carbohydrate affinities, antiobody-carbohydrate binding, etc.). ^1–5 In addition, the different chemistries exhibited by the flourinated carbohydrates have made them important reagents in both metabolic studies and disease diagnosis such as the use of 2-deoxy-2-18f]-D-fluoroglucose in positron emission tomography. 6,7 Becasue of their widespread utlity, the synthesis of fluorinated carbohydrates is of importance. However, the Introduction of fluorine into a carbohydrate moiety can be an arduous task because of (1) the protection and deprotection steps required to set up the desired hydroxyl group for the introduction of fluoride, (2) the low nucleophilicity fo fluoride ion, and (3) fluoride ion catalyzed elimination reactions. 8,9 The search for Milder and more selective methods for the introduction of fluorine into Carbohydrates has continued at a rapid pace and it is appropriate to review som of the recent results.