作者:Kyeong Lee、Wen Zhou、Laura-Lee C. Kelley、Cory Momany、Chung K. Chu
DOI:10.1016/s0957-4166(02)00438-x
日期:2002.8
A series of fluorinated pyranosyl nucleosides in d- and l-configurations, 16, 19–20, 25, 28–29, have been synthesized. Starting from 1,2-O-isopropylidene-d-glyceraldehyde, homologated templates (3S)-6 and (3R)-6 were prepared by vinylation of fluoroenal 3, which were transformed to give allylic alcohols, 8 and 21, in three steps, respectively. The key intermediate triols 9 and 22 were obtained by O-benzoyl
在D-和L-构型的一系列氟化吡喃核苷,16,19 - 20,25,28 - 29,已被合成。从1,2-开始ö异亚丙基d甘油醛,同系化的模板(3小号- )6和(3 - [R )- 6通过的fluoroenal乙烯化制备3,将其转化,得到烯丙基醇,8和21,在三个步骤,分别。关键的中间体三元醇9和22是通过O-苯甲酰基从伯羟基迁移到相邻的仲羟基。在碱性条件下,9和22的闭环反应分别得到不饱和吡喃糖基衍生物10和23,而在酸性条件下形成不饱和呋喃糖基化合物12。然后在Vorbrüggen条件下用甲硅烷基化的碱基对乙酸吡喃酯基进行N-糖基化反应,得到受保护的核苷,然后将其转化为游离的核苷。然而,不饱和呋喃糖基中间体12的缩合没有提供所需的核苷。合成化合物的结构和立体化学分配基于16a和16b的NOESY光谱以及19a的X射线晶体结构。