抄録
Nucleoside antimetabolites act an important role in the fields of cancer and viral chemotherapies. To search new agents effective for tumor and virus, many attempts were made for synthesizing novel nucleoside derivatives. Construction of the glycosidic bond is a key reaction to synthesize new nucleoside derivatives. We have been focused the synthesis of novel biologically active nucleoside derivatives by developing novel “glycosylation” reactions. Our first successful example was the synthesis of 4′-thionucleoside by using the Pummerer-type thioglycosylation reaction. As a result, we found potent antineoplastic nucleoside, 4′-thioFAC, and some novel 4′-thionucleosides possessing antiherpes virus activities. Secondary, we developed a new entry to isonucleosides in which the Mitsunobu reaction with neighboring sulfur assistance was employed as a nucleobase introducing reaction. We also developed a conceptually new method for synthesizing carbocyclic nucleosides based on hypervalent iodine chemistry. The mechanism of this oxidative coupling reaction was investigated.