Pyrimidine S- and N-cyclonucleosides. Synthesis of 6,2'(and 5')-S- and N-cyclouridines. Nucleosides and nucleotides. XXXII.
作者:SUSUMU SHIBUYA、TOHRU UEDA
DOI:10.1248/cpb.28.939
日期:——
The synthesis of S- and N-cyclouridines, which are "anti"-fixed cyclonucleosides, is described. Bromination of S2, 2'-cyclo-2-thiouridine afforded the 5-bromo derivative. Cleavage of the S2, 2'-cyclo linkage of the 5-bromo derivative with methoxide resulted in the formation of S6, 2'-cyclo-2-O-methyluridine by intramolecular conversion of the S2, 2'-linkage to an S6, 2'-linkage, and this was further converted to the corresponding S6, 2'-cyclo derivatives of uridine, isocytidine and 2-thouridine. Similarly, 2', 3'-O-isopropylidene-S2, 5'-cyclo-2-thiouridine was converted to the 2', 3'-O-isopropylidene-S6, 5'-cyclo derivatives of uridine, isocytidine, and 2-thiouridine. 6-Methylaminouridine was cyclized by treatment with diphenyl carbonate to N6, 2'-cyclo-6-methylaminouridine. Cyclization with triphenylphosphine and diethyl azodicarboxylate gave the N6, 5'-cyclo derivative of 6-methylaminouridine.
描述了S-和N-环尿苷的合成,这些是“反”固定环核苷。S2,2'-环-2-硫尿苷的溴化反应产出了5-溴衍生物。通过甲氧基对5-溴衍生物的S2,2'-环连接的裂解,实现了S6,2'-环-2-O-甲基尿苷的形成,此过程通过S2,2'-连接转化为S6,2'-连接。此外,进一步转化为相应的尿苷、异尿苷和2-硫尿苷的S6,2'-环衍生物。同样,2',3'-O-异丙基腈化的S2,5'-环-2-硫尿苷被转化为尿苷、异尿苷和2-硫尿苷的2',3'-O-异丙基腈化的S6,5'-环衍生物。用二苯碳酸酯处理6-甲氨基尿苷使其环化为N6,2'-环-6-甲氨基尿苷。与三苯基膦和二乙基偶氮二羧酸酯的环化反应生成了6-甲氨基尿苷的N6,5'-环衍生物。