Selective introduction of a fluorine atom into carbohydrates and a nucleoside by ring-opening fluorination reaction of epoxides

Ring-opening fluorination reactions of epoxides using tetrabutylammonium bifluoride (TBABF)-KHF2, or Et3N-3HF under microwave irradiation were applied for the introduction of a fluorine atom into the carbohydrate molecules. When TBABF-KHF2 was used as the fluorination reagent, a fluorine atom was introduced regioselectively and various functional groups can tolerate the conditions. When Et3N-3HF was used under microwave irradiation, the reaction time could be remarkably shortened compared with the conventional oil-bath heating.