A concise asymmetric synthesis of (+)-swainsonine (ent-1) is described starting from 2, which was readily prepared from commercially available L-glutamic acid. The method features installation of the indolizidine ring via an intramolecular cyclisation of α-sulfinyl carbanion as a key step. (+)-Swainsonine was obtained in 11.8% overall yield in 10 steps.
本文介绍了一种简便的 (+)-swainsonine (ent-1) 不对称合成方法,该方法以 2 为起点,后者很容易从市售的
L-谷氨酸中制备出来。该方法的关键步骤是通过 α-亚磺酰基碳酰离子的分子内环化来安装
吲哚嗪环。通过 10 个步骤,以 11.8%的总收率获得了 (+)-Swainsonine 。