Introduction of a benzyl group onto the 2'-OH of 6-chloropurine 3'-O-benzoylriboside.

A new method to introduce a benzyl group onto the 2'-OH of purine ribonucleoside is described. Thus, 6-chloropurine 3'-O-benzoylriboside and its 5'-O-trityl congener were condensed with benzyl alcohol using the Mitsunobu reaction to give the 2'-O-benzyl derivative. The yields were varied from 4.6 to 62.9% depending on the solvent. The product was converted to adenosine, indicating that the stereochemistry at C-2' is retained.