An efficient synthesis of thioisomunchnones derived from uracils and uridine: novel type of mesoionic nucleosides

reaction: see text] Synthetic approaches to a variety of thioisomunchnones derived from uracils and uridine are described, as well as their properties and cycloaddition tendencies. The anhydro-3-hydrocy-2-phenyl-6-(2',3',5'-tri-O-benzoyl-beta-D-ribofuranosyl)thiazolo3,2-c]pyrimidine-5(6H)-on-4-ium hydroxide represents a novel class of mesoionic nucleosides.