SYNTHESIS OF DEOXYRIBONUCLEOSIDE DERIVATIVE

PURPOSE:To obtain the derivative into which a desired nucleophilic group is introduced in the saccharide moiety simply under mild conditions by allowing a nucleophilic reagent to react with an anhydronucleoside of a specific structure in the presence of an acid catalyst. CONSTITUTION:In the presence of an acid catalyst, preferably Lewis acid, for example, boron trifluoride, a nucleophilic reagent, preferably a halide, for example, lithium halide, is allowed to react with an anhydro cyclonucleoside in which the hydroxy group in the saccharide moiety other than those participating the formation of said anhydro ring is protected with a group, preferably 1,1,3,3- tetraisopropyldisiloxane-1,3-diyl group, preferably a pyrimidine cyclonucleoside, to provide the derivative, for example, (2'R)-3',5'-0-(1,1,3,3-tetra- isopropyldisiloxane-1,3'-diyl)-2'-bromo-2'-deoxyuridine.