A Concise Stereoselective Route to the Indoline Spiroaminal Framework of Neoxaline and Oxaline
作者:Toshiaki Sunazuka、Tatsuya Shirahata、Satoshi Tsuchiya、Tomoyasu Hirose、Ryuma Mori、Yoshihiro Harigaya、Isao Kuwajima、Satoshi Ōmura
DOI:10.1021/ol050077y
日期:2005.3.1
stereoselective synthesis of tetracyclic intermediate, the indoline spiroaminal 3 for neoxaline (1) and oxaline (2), has been accomplished. The key step of the stereoselective synthesis of 3 was the Lewis acid mediated transcyclization of 4 to the diaminal 18, and the tungstate-catalyzed oxidation of 18 to obtain the nitrone 19, which easily cyclizes to the indoline spiroaminal framework 3. [structure:
已经完成了四环中间体,即新草碱(1)和草胺(2)的二氢吲哚螺环胺3的立体选择性合成。3的立体选择性合成的关键步骤是路易斯酸介导的4到二氨基18的路易斯酸的环化,以及钨酸盐催化的18氧化,得到的硝酮19,该环很容易环化成二氢吲哚螺环结构3。文本]