Kazimierczuk Z, Revankar G R, Robins R K
Nucleic Acids Res. 1984 Jan 25;12(2):1179-92. doi: 10.1093/nar/12.2.1179.
Direct glycosylation of the sodium salt of 4,6-dichloro- or 4,6-dibromo-2-methylthiopyrrolo[2,3-d]pyrimidine with 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide gave good yield of the corresponding N7-glycosylated pyrrolo [2,3-d]pyrimidine. The intermediate 4-amino-6-chloro-2-methylthio-7-beta-D-ribofuranosylpyrrolo[2,3-d] pyrimidine provided a new synthetic route to tubercidin, via 6-chlorotubercidin. 6-Chloro-2-methoxytubercidin was also obtained from 10 via the methylsulfone. Application of this glycosylation procedure to 4,6-dichloro- or 4,6-dibromo-2-methylpyrrolo [2,3-d]-pyrimidine also furnished the corresponding N7-glycosyl derivatives with beta-configuration. Dehalogenation of gave 2-methyl-tubercidin and bromination with bromine in a buffered solution gave 5,6-dihalo-2-methyltubercidin. Several new 2,6-disubstituted tubercidin derivatives were prepared from these glycosyl intermediates. This new sodium salt glycosylation procedure was found to be superior to other procedures for the total synthesis of these halogenated 7-deazapurine nucleosides.
4,6-二氯-或4,6-二溴-2-甲基硫代吡咯并[2,3-d]嘧啶钠盐与2,3,5-三-O-苯甲酰基-D-呋喃核糖基溴直接糖基化反应，以良好的产率得到相应的N7-糖基化吡咯并[2,3-d]嘧啶。中间体4-氨基-6-氯-2-甲基硫代-7-β-D-呋喃核糖基吡咯并[2,3-d]嘧啶通过6-氯杀结核菌素提供了一条合成杀结核菌素的新路线。6-氯-2-甲氧基杀结核菌素也可从10经甲砜制得。将此糖基化方法应用于4,6-二氯-或4,6-二溴-2-甲基吡咯并[2,3-d]嘧啶，也得到了相应的具有β-构型的N7-糖基衍生物。脱卤得到2-甲基杀结核菌素，在缓冲溶液中用溴溴化得到5,6-二卤-2-甲基杀结核菌素。从这些糖基中间体制备了几种新的2,6-二取代杀结核菌素衍生物。发现这种新的钠盐糖基化方法优于其他用于这些卤代7-脱氮嘌呤核苷全合成的方法。
