A Stereoselective Approach to β-<scp>l</scp>-Arabino Nucleoside Analogues: Synthesis and Cyclization of Acyclic 1′,2′-<i>syn</i><i>N</i>,<i>O</i>-Acetals
作者:Starr Dostie、Michel Prévost、Yvan Guindon
DOI:10.1021/jo3012754
日期:2012.9.7
Reported herein is a novel and versatile strategy for the stereoselective synthesis of unnatural β-l-arabinofuranosyl nucleoside analogues from acyclic N,OTMS-acetals bearing pyrimidine and purine bases. These unusual acetals undergo a C1′ to C4′ cyclization where the OTMS of the acetal serves as the nucleophile to generate 2′-oxynucleosides with complete retention of configuration at the C1′ acetal
本文报道的是的立体选择性合成的新颖和通用的策略不自然β-升-arabinofuranosyl核苷类似物从非环状Ñ,OTMS -acetals轴承嘧啶和嘌呤碱基。这些不寻常的缩醛经过C1'至C4'环化,其中缩醛的OTMS充当亲核试剂,生成2'-氧核苷,并完全保留了C1'缩醛中心的构型。Ñ,OTMS被非对映选择性甲硅烷基化由核碱基的添加在MgBr的存在下获得到非环状polyalkoxyaldehydes -acetals 2 ·OET 2。该策略报告是通过提供不自然的立体选择性访问寻址重要的合成挑战升核苷从容易访问的池起始d -sugars和,重要的是,通过允许在空间上具有挑战性的1',2'-的形成CIS核苷。从易于获得的D-木糖以7-8个步骤合成了各种各样的核苷类似物。