Synthesis of fluorocyclobutanones and their use in the synthesis of fluoronucleosides

Fluorocyclobutanones can be prepared from reaction of hydroxycyclobutanones with diethylaminosulfur trifluoride (DAST). Other fluorine containing cyclobutanones can be prepared by alkene/fluoroketene cycloadditions. The photochemical ring-opening of these synthetic intermediates with 6-chloropurine produces fluorinated nucleoside analogs.