An alternative synthesis of 3′-deoxy-3′-fluoro-d-ribofuranosyl nucleoside, an important fragment of antitumor active cyclic dinucleotide

An alternative synthesis of 3′-deoxy-3′-fluoro-d-ribofuranosyl nucleoside from d-arabinose is disclosed. Inversion of configuration at C3 on d-arabinoside promoted by DAST reagent is utilized to form lyxo-configured furanoside. After a sequence of fluorination, acidic methanolysis, triflation and displacement by -OBz. 3′-deoxy-3′-fluoro-d-ribofuranoside is obtained, which is then transformed to 1-O-benzoyl derivative. The synthesis of three 3′-deoxy-3′-fluoro-d-ribofuranosyl nucleosides, which can be served as fragment of antitumor active cyclic dinucleotide is finally completed through Vorbrüggen glycosylation .