Preparation of 2,2′-anhydronucleosides: regio- and stereoselective modifications of the base and sugar moieties
作者:Rafael Robles、Concepción Rodrı́guez、Isidoro Izquierdo、Marı́a T Plaza、Antonio Mota、Luis Álvarez de Cienfuegos
DOI:10.1016/s0957-4166(00)00272-x
日期:2000.8
of the configuration at C-2′, by heating in DMF with n-dibutyltin oxide. Regio- and stereospecific opening at C-2′ of the 2,2′-ring in compounds 10, 11, and 12 with sodium azide afforded the related 2′-azido-2′-deoxynucleosides 16, 17 and 18, respectively. Action of sodium hydroxide on 12 caused the regioselective opening of the above-mentioned ring at C-2 with retention of the configuration at C-2′
2'-脱氧-2'- iodonucleosides 4 - 9,从适当保护的呋喃烯糖得到的1和2具有不同的甲硅烷基化嘧啶碱,转化成相应的2,2'-脱水核苷10 - 15与C-的构型反转2',通过在DMF中与正二丁基氧化锡一起加热。在化合物中存在的2,2'-环的C-2'区域选择性和立体有择的开口10,11,和12与叠氮化钠,得到相关2'-叠氮基-2'-脱氧核苷16,17和18分别。氢氧化钠对图12的C 12导致上述环在C-2处的区域选择性打开,同时保留了在C-2'处的构型,得到19。化合物19可以通过公认的方法直接转换为18。另一方面,化合物15可以通过在N-3–C-2'上与2,2'的开环同时存在的烯丙基溴的区域和立体选择性加成而转化为相关的2',3'-脱水核苷23。将C-2'处的构型反转,得到中间体2'-溴-2'-脱氧核苷21,随后将其用甲醇钠处理,得到23。