作者:R. Paul Gagnier、Michael J. Halat、Brian A. Otter
DOI:10.1002/jhet.5570210243
日期:1984.3
Unlike imidazo[4,5-d]pyridazin-4(5H)-one (1a), which undergoes ribosylation at N-6 in the Vorbruggen procedure for nucleoside synthesis, the 5-benzyloxymethyl derivative 12 undergoes ribosylation at N-1 and N-3 to give a separable mixture of 14 and 15. Removal of the N-5 blocking groups from 14 and 15 by treatment with boron trichloride at −78° affords the intermediates 16 and 17, which were debenzoylated
与咪唑并[4,5- d ]哒嗪-4(5 H)-one(1a)在核苷合成的Vorbruggen程序中在N-6处进行核糖基化不同,5-苄氧甲基衍生物12在N-1处进行核糖基化。 N-3给出14和15的可分离混合物。通过在-78°下用三氯化硼处理将N-5封闭基团从14和15除去,得到中间体16和17,将它们进行脱苯甲酰化,得到4-氧代核苷5和6。16和17的Thion,然后进行S-甲基化和氨解反应,生成4-氨基核苷2和3。这些核苷的糖基化位点通过结合使用1 H和13 C nmr数据进行分配,尤其是测量基本质子的自旋晶格弛豫时间(T 1)。使用这些技术,表明先前报道为3的核苷实际上是N-6异构体。