Synthesis of 9-[2-O-(2-Methoxyethyl)-β-D-Ribofuranosyl]purines Using 1- Methanesulfonyloxy-2-Methoxyethane

1-Methanesulfonyloxy-2-methoxyethane (1; MsO-MOE) was used for alkylation of adenosine and 2-aminoadenosine. 2'-O-MOE derivatives of adenosine (3), 2-aminoadenosine (7) and guanosine (10) have been prepared in 47, 44 and 81% isolated yields, respectively. The stereochemistry of the pentofuranose rings of the isomeric 2'-O-MOE and 3'-O-MOE purine nucleosides is very similar and, moreover, alkylation of either 2'- or 3'-hydroxyls has practically no effect upon the stereochemistry of the parent nucleosides.