Synthesis and optical properties of 2'-deoxy-8,2'-methanoguanosine.
作者:Akira MATSUDA、Kazuyuki WATANABE、Tadashi MIYASAKA、Tohru UEDA
DOI:10.1248/cpb.37.298
日期:——
The synthesis of a new carbon-bridged cyclopurine nucleoside, 2'-deoxy-8, 2'-methanoguanosine (25), which is fixed in a high-anti torsional angle region, was accomplished. 2-Acetamido-6-ethoxy-8-methanesulfonyl-9-(3, 5-di-O-acetyl-2-O-tosyl-1-β-D-ribofuranosyl)purine (18) was cyclized with carbanions of malonic esters, followed by sequential deblocking and decarboxylation to afford 25. The ultraviolet spectra of 25 in neutral solution revealed two separated bands corresponding to their B1u and B2u transitions, which was rather similar to the case of its O6-ethyl derivative (22), but quite different from the previously reported 8, 2'-methanoguanosine (26), a ribosyl counterpart of 25. The circular dichroism spectra of these cyclonucleosides are also discussed.
我们合成了一种新的碳桥环嘌呤核苷--2'-脱氧-8,2'-甲基鸟苷(25),它固定在高抗扭角区域。2-Acetamido-6-ethoxy-8-methanesulfonyl-9-(3, 5-di-O-acetyl-2-O-tosyl-1-β-D-ribofuranosyl)purine (18)与丙二酸酯的碳化物发生环化反应,然后依次脱锁和脱羧,得到 25。25 在中性溶液中的紫外光谱显示出两个分离的波段,分别对应于它们的 B1u 和 B2u 过渡,这与其 O6-乙基衍生物(22)的情况相当相似,但与之前报道的 8,2'-甲基鸟苷(26)(25 的核糖基对应物)截然不同。本文还讨论了这些环核苷的圆二色光谱。