Exchange radioiodination produces inversion at C-4 of 1-(4-deoxy-4-iodo-?-D-xylopyranosyl)-2-nitroimidazole
作者:R.F. Schneider、W.A. Price、J.D. Chapman
DOI:10.1002/jlcr.596
日期:2002.7
The title compound, 3a, when exchange labeled with 125I results in three new labeled products. The major labeled product (84.1%) is 1-(4-deoxy-4-iodo-β-L-arabinopyranosyl)-2-nitroimidazole, 3b, that could result from inversion of configuration at C-4. Exchange labeling carried out under conditions of kinetic control yielded dramatically different product ratios than thermodynamic equilibrium reactions. Confirmation of these results was established by extensive 1HNMR spectral analyses. A possible mechanism is presented. Copyright © 2002 John Wiley & Sons, Ltd.
当标题化合物 3a 用 125I 进行交换标记时,会产生三种新的标记产物。主要的标记产物(84.1%)是 1-(4-脱氧-4-碘-β-L-阿拉伯吡喃糖基)-2-硝基咪唑,即 3b,这可能是由于 C-4 的构型反转造成的。在动力学控制条件下进行的交换标记与热力学平衡反应产生的产物比率大不相同。大量的 1HNMR 光谱分析证实了这些结果。本文提出了一种可能的机理。Copyright © 2002 John Wiley & Sons, Ltd. All Rights Reserved.