“…In the meantime, Pinto and co-workers , succeeded in the stereoselective synthesis of a series of 4′-seleno- d -ribonucleosides ( 4 ) and applied the thymidine variant to the synthesis of oligonucleotides, which revealed a unique conformational shift arising from the introduced selenonucleoside. Thus, selenosugars and selenonucleosides are interesting targets of organic synthesis as they would possess potential biological activities, such as enzyme inhibitors, , antioxidants, , antibiotics, − and so forth . However, 4-selenotherofuranose derivatives, which have trans configuration for the two dihydroxy substituents at the 2,3-positions such as 2 and 3a and a glycoside bond at the anomeric position, are not available in the current selenosugar library.…”