α-Phosphono Lactone Analogues of Cytidine and Cytosine Arabinoside Diphosphates: Synthesis via Ring Closing Metathesis
作者:Xuemei Chen、David F. Wiemer
DOI:10.1021/jo0300136
日期:2003.8.1
cytidine aldehydes, and gave some stereoselectivity in additions to an aldehyde derivative of ara-C. The resulting homoallylic alcohols were used as substrates in attempted Knovenagel and Horner-Wadsworth-Emmons condensations, but elimination was found to predominate over lactone formation under the conditions employed. The desired alpha-phosphono lactones could be prepared through a reaction sequence that
核苷胞苷和胞嘧啶阿拉伯糖苷的α-膦酸内酯衍生物已由相应的核苷醛制备。发现与这些醛的烯丙基化反应的立体化学结果取决于对2'-和3'-羟基的保护基的选择以及在某种程度上取决于所使用的路易斯酸催化剂的性质。最终,发现条件有利于来自不同胞嘧啶醛的5'R或5'S非对映异构体,并且除了ara-C的醛衍生物之外还提供了一些立体选择性。在尝试的Knovenagel和Horner-Wadsworth-Emmons缩合尝试中,所得的均丙醇被用作底物,但发现在所采用的条件下,消除作用比内酯的形成更为重要。