Use of diethylaminosulphur trifluoride (DAST) in the preparation of synthons of carbocyclic nucleosides

Abstract
Diethylaminosulphur trifluoride (DAST) converted the protected amino triol (4) into the fluorine-containing compounds (8) and (10). The same reagent converted the alcohol (9) into compounds (10), (5), and (11) and transformed the azido alcohol (15) into the fluoroazides (16) and (19). The fluorinated compounds (5), (8), and (16) are useful synthons for fluorocarbocyclic nucleosides. The effect of neighbouring groups on the course of some DAST reactions is discussed.