| 摘要 |
5-Azapyrimidine nucleosides of the formula WHEREIN X is NH or an oxygen atom and Z is a free or blocked sugar residue having cytotoxic, antiviral, enzyme-inhibiting, immunosuppressive, anti-inflammatory and antipsoriatic activity are prepared by the reaction in the presence of a Lewis acid, of a 1-O-acyl-, 1-O-alkyl- or 1-holoderivative of a blocked sugar with a compound of the general formula wherein D is a silylated or alkylated O-group and E is a silylated or alkylated O- or NH-group, the blocking groups of the sugar residue thereafter optionally being split off in a conventional manner to produce the corresponding free nucleoside. |
