Nucleophilic substitution approach to 4′-substituted thymidines by employing 4′-benzenesulfonyl leaving group
作者:Hisashi Shimada、Satoshi Kikuchi、Saori Okuda、Kazuhiro Haraguchi、Hiromichi Tanaka
DOI:10.1016/j.tet.2009.05.078
日期:2009.8
Synthesis of 4′-substituted thymidines was investigated based on nucleophilic substitution using organosilicon and organoaluminum reagents. Two substrates having a benzenesulfonyl leaving group at the 4′-position were prepared for this purpose: 1-[4-benzenesulfonyl-3,5-bis-O-(tert-butyldimethylsilyl)-2-deoxy-α-l-threo-pentofuranosyl]thymine (8α) and the 4′-(benzenesulfonyl)thymidine derivative (8β)
使用有机硅和有机铝试剂,基于亲核取代作用,研究了4'-取代的胸苷的合成。为此目的,制备具有苯磺酰的离去基团在4'位两个基板:1- [4-苯磺酰基-3,5-二- Ö - (叔丁基二甲基)-2-脱氧α-升-苏-戊呋喃糖基]胸腺嘧啶(8α)和4'-(苯磺酰基)胸腺嘧啶核苷衍生物(8β)。的反应8α用有机硅试剂(ME 3 SICH 2 CH CH 2和Me 3的SiN 3),其与组合的SnCl 4优先给出4′-取代的β- d-异构体:4′-烯丙基(12β)和4′-叠氮基(15β)衍生物。然而,推测8α与AlMe 3的反应产生了4′-甲基-α - l-异构体(16α)作为主要产物,推测是通过离子对机理。通过在该反应中使用底物8β,仅以高收率获得了4'-甲基胸苷衍生物(16β)。还通过使8β与相应的有机铝试剂反应合成了4'-乙基(20β)和4'-氰基(24β)衍生物。