Total synthesis of (−)-codonopsinine via regioselective and diastereoselective amination using chlorosulfonyl isocyanate
作者:Young Jae Choi、Yoo Chang Kim、Sook Jin Park、Jun Min Jung、Yeon Su Kim、In Su Kim、Young Hoon Jung
DOI:10.1016/j.tet.2017.06.002
日期:2017.7
The total synthesis of (−)-codonopsinine (1) from the readily available (S)-3-chloropropan-1,2-diol is described. The key steps for the preparation of (−)-codonopsinine (1) involve the regioselective and diastereoselective amination of anti-1,2-dibenzyl ether 11 using chlorosulfonyl isocyanate and intramolecular amidomercuration to form the pyrrolidine ring. Notably, the reaction between anti-1,2-dibenzyl
描述了从容易获得的(S)-3-氯丙烷-1,2-二醇中合成(-)-codonopsinine(1)的全过程。制备(-)-codonopsinine(1)的关键步骤包括使用氯磺酰基异氰酸酯对抗-1,2-二苄基醚11进行区域选择性和非对映选择性胺化,以及分子内酰胺化反应以形成吡咯烷环。值得注意的是,抗-1,2-二苄基醚与氯磺酰基异氰酸酯在0°C的甲苯中反应生成了相应的抗-1,2-氨基醇12a,这是一种主要产物,具有非对映体选择性(anti:syn = 29:1)。该观察结果可以通过邻近组的参与导致立体化学的保留来解释。