Tandem Radical Fragmentation/Cyclization of Guanidinylated Monosaccharides Grants Access to Medium-Sized Polyhydroxylated Heterocycles.

The fragmentation of anomeric alkoxyl radicals (ARF) and the subsequent cyclization promoted by hypervalent iodine provide an excellent method for the synthesis of guanidino-sugars. The methodology described herein is one of the few existing general methodologies for the formation of medium-sized exo- and endoguanidine-containing heterocycles presenting a high degree of oxygenation in their structure.