Synthesis of Oxepane Ring Containing Monocyclic, Conformationally Restricted Bicyclic and Spirocyclic Nucleosides from <scp>d</scp>-Glucose: A Cycloaddition Approach
作者:Subhankar Tripathi、Biswajit G. Roy、Michael G. B. Drew、Basudeb Achari、Sukhendu B. Mandal
DOI:10.1021/jo070846m
日期:2007.9.1
C-3-O-allyl, (ii) C-4 vinyl and a C-3-O-tethered nitrone, and (iii) C-5 nitrone and C-4-allyloxymethyl generated tetracyclic isoxazolidinooxepane/-pyran ring systems upon intramolecular nitrone cycloaddition reactions. Deprotection of the 1,2-acetonides of these derivatives followed by introduction of uracil base via Vorbrüggen reaction condition and cleavage of the isooxazolidine rings as well as of benzyl
具有(i)C-5硝酮和C-3- O-烯丙基,(ii)C-4乙烯基和C-3- O的碳水化合物衍生的底物分子内的硝酮环加成反应生成的四环异恶唑烷氧杂环庚烷/吡喃环系统生成了束缚的硝酮,以及(iii)C-5硝酮和C-4-烯丙氧基甲基。将这些衍生物的1,2-丙酮化物脱保护,然后通过Vorbrüggen反应条件引入尿嘧啶碱基,并通过转移氢解作用裂解异恶唑烷环以及苄基,得到含有双环和螺环核苷的氧杂环丁烷环。通过切割异恶唑烷和呋喃糖环,将产生的氨基官能团与5-氨基-4,6-二氯嘧啶偶联,环化为嘌呤环,最后进行氨解,制备相应的基于氧杂环丁烷的核苷类似物。