| 摘要 |
<p>1313411 Protected pyrimidine nucleosides SCHERING AG 13 April 1970 [11 April 1969 23 Aug 1969] 17443/70 Heading C2C Pyrimidine nucleosides in which the hydroxyl groups in the sugar moiety are protected are prepared by reaction of a 1-O-acyl-, 1-O-alkyl- or 1-halogeno-sugar in which the hydroxyl groups are protected with a pyrimidine derivative containing at least one group selected from O-, S- and N-alkyl and -silyl groups, in the presence of a Lewis acid that is soluble in an organic solvent. The sugar is preferably ribose, deoxyribose, arabinose or glucose and the pyrimidine derivative is preferably of the general formula wherein R is a hydrogen or halogen atom or a C 1-4 alkyl, nitro or cyano group, E is a silylated or alkylated O- or S-group, D is a silylated or alkylated O- or B-N-group, in which B is a hydrogen atom or an alkyl, aryl or aralkyl group and Y is a nitrogen atom or a CH group. The protecting groups may be acetyl, benzoyl, p-chlorobenzoyl, p-nitrobenzoyl, p-toluyl and benzyl groups.</p> |
