DIVERGENT AND STEREOCONTROLLED APPROACH TO THE SYNTHESIS OF URACIL NUCLEOSIDES BRANCHED AT THE ANOMERIC POSITION
DIVERGENT AND STEREOCONTROLLED APPROACH TO THE SYNTHESIS OF URACIL NUCLEOSIDES BRANCHED AT THE ANOMERIC POSITION
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异头位支化尿嘧啶核苷的发散立体控制合成方法
DOI：
10.1021/jo00108a031
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发表时间：
1995
影响因子：
3.6
通讯作者：
T. Miyasaka
中科院分区：
文献类型：
--
作者：
Y. Itoh;K. Haraguchi;Hiromichi Tanaka;Eisen Gen;T. Miyasaka
NBS/戊酸（溴代戊酰氧基化）与1 -[3,5 -二-0-（铁-丁基二甲基硅基）-2-脱氧-d -乙基/铁-戊- 1 -烯呋喃基]尿嘧啶的亲电加成(2)，易于从0* 12,2 '-无氢尿嘧啶中获得，构型为1 -[2-溴- 3,5 -二-0-（叔丁基二甲基硅基）-2-脱氧- 1 -（戊酰氧基）-/？- d -ara-二氟脲基]尿嘧啶(7)立体选择性。该化合物(7)在位置上具有离去基和2'-/3-Br，可以发挥嵌合作用，通过使用有机硅和有机铝试剂亲核取代，作为多功能中间体，用于立体控制合成各种类型的l'- c分支衍生物。整个序列构成天然存在的核苷转化为在端粒位置分支的类似物的第一个例子。
Electrophilic addition of NBS/pivalic acid (bromopivaloyloxylation) to l-[3, 5-bis-0-(feri-butyldi-methylsilyl)-2-deoxy-D-ezyi/iro-pent-l-enofuranosyl] uracil (2), readily accessible from 0* 12, 2'-anhydro-uridine, furnished l-[2-bromo-3, 5-bis-0-(terf-butyldimethylsilyl)-2-deoxy-l-(pivaloyloxy)-/?-D-ara-binofuranosyl] uracil (7) stereoselectively. This compound (7), having a leaving group at theposition as well as 2'-/3-Br that could exert anchimeric assistance, serves as versatile intermediate for the stereocontrolled synthesis of various types of l'-C-branched derivatives through nucleophilic substitutions by the use of organosiliconand organoaluminum reagents. The whole sequence constitutes the first example of the conversion of a naturally-occurring nucleoside to the analogues branched at the anomeric position.