Transformation of Hemiacetal Hydroxy Groups in Free Saccharides Using a Formamidinium-type Electrophile

Formamidinium-type dehydrating reagents such as 2-chloro-1,3-dimthylimidazolinium chloride are useful as selective activators toward hemiacetal hydroxy groups at the sugar-reducing end in an aqueous media. This synthetic method enables us to obtain various sugar-containing compounds directly from the corresponding free saccharides using corresponding nucleophiles. Azide and aryl thiol act as suitable nucleophiles for this method and the resulting compounds are used as intermediates for glycoconjugates. This study aims to describe the progress of direct modification of the sugar-reducing end using a formamidinium-type electrophile.