| 摘要 |
<p>PROBLEM TO BE SOLVED: To make an intermediate that gives 2'-fluorinated and 3'-deoxygenated nucleosides which is useful as an antiviral agent obtainable through efficient substitution in its 2'-position by using a novel compound in which a halogen is substituted for its 6-position of the nucleic acid base and modifying the saccharide moiety on its 3' and 5'-positions with different specific protecting groups thereby efficiently replacing the 2'-position. SOLUTION: The compound represented by formula I (X is chlorine, bromine or iodine; R<1> and R<2> are different from each other, and hydroxyl group- protecting groups which cannot be deprotected under the same conditions) is fluorinated, azidated or cyanided to give 6-substituted-9-(2-deoxy-2-substituted-β- D-arabinofuranosyl)purine derivative of formula II (Y is fluoro, azide, cyano). The compound of formula I is obtained by protecting 6-chloropurine riboside in its 3'- and 5'-position with different protecting groups that cannot be deprotected under the same conditions in order. The compound of formula II is novel.</p> |
