A cyclic dinucleotide with a four-carbon 5′-C-to-5′-C connection; synthesis by RCM, NMR-examination and incorporation into secondary nucleic acid structures
作者:Pawan K. Sharma、Birgitte H. Mikkelsen、Mikkel S. Christensen、Katrine E. Nielsen、Claus Kirchhoff、Søren L. Pedersen、Anders M. Sørensen、Kirsten Østergaard、Michael Petersen、Poul Nielsen
DOI:10.1039/b603830a
日期:——
as a substrate for a ring-closing metathesis (RCM) reaction and after deprotection, a 1 : 1 mixture of E- and Z-isomers of a cyclic dinucleotide with an unsaturated 5'-C-to-5'-C connection was obtained. Alternatively, a hydrogenation of the double bond and deprotection afforded a saturated cyclic dinucleotide. An advanced NMR-examination confirmed the constitution of this molecule and indicated a restriction
通过应用立体选择性烯丙基化方法由胸苷制备5'-C-烯丙基胸苷衍生物,并确认了其5'(S)-构型。从该核苷衍生物制备适当保护的结构单元,并使用标准亚磷酰胺化学方法偶联,得到具有两个5'-C-烯丙基的二核苷酸。该分子用作闭环复分解(RCM)反应的底物,去保护后,是环状二核苷酸的E-和Z-异构体与不饱和5'-C-至-5'-的1:1混合物。获得了C连接。或者,双键的氢化和脱保护得到饱和的环状二核苷酸。先进的NMR检查证实了该分子的结构,并表明了其整体构象自由度受到限制。在改变保护基策略之后,获得了具有5'-O-位的饱和环状二核苷酸的亚磷酰胺结构单元,其被保护为pixyl ether,并且磷酸盐被保护为甲基磷酸三酯。该构件用于制备由于环二核苷酸部分而具有中央人工弯曲的两个14-mer寡核苷酸。发现这些可以使双链体不稳定,稍微使凸起的双链体不稳定,但是在一定程度上可以稳定高Mg(2+)浓度的三向连接。