Search for a simpler synthetic model system for intramolecular 1,3-dipolar cycloaddition to the 5,6-double bond of a pyrimidine nucleoside
作者:Tadashi Sasaki、Katsumaro Minamoto、Toshimichi Suzuki、Shunsuke Yamashita
DOI:10.1016/0040-4020(80)80036-6
日期:1980.1
regiospecifically transformed to 1,2,3-triazole derivatives, 17,18 and 19. Heating 1-(4-azidobutyl)-5-bromouracil (20) yielded 3,9-tetramethylene-8-azaxanthine (22). 9 with NBA gave 1,06-tetramethylene-5-bromo-6-hydroxy-5,6-dihydrouracil (24) and the 5-brominated analog of 9 (25). The 4-functionalized butyl side chain proved to serve as a substitute for the 5'-functionalized sugar moiety in pyrimidine ribonucleosides
为了寻找一个更简单的模型系统来研究核苷中的碱基和5'-官能化糖部分之间的分子内热反应,1-(3-叠氮基丙基)尿嘧啶(2),1-(4-叠氮基丁基)嘧啶(12和13)和1-(5- azidopentyl)尿嘧啶(14)通过合成相应的ω-苯甲酰氧基(6,7和8)和ω-羟基-嘧啶(9,10和11)。加热2得到1,N 6-三亚甲基-6-氨基尿嘧啶(4),同时加热12和13得到N。1 -C 6裂解的加成产物。分别为15和16。15是区域专一性转化为1,2,3-三唑衍生物,17,18和19。加热1-(4-叠氮丁基)-5-溴尿嘧啶(20),得到3,9-四亚甲基-8-氮杂黄嘌呤(22)。NBA的9产生1,0 6-四亚甲基-5-溴-6-羟基-5,6-二氢尿嘧啶(24)和9的5溴类似物(25)。事实证明4-官能化的丁基侧链可替代嘧啶核糖核苷中的5'-官能化的糖部分。