A divergent approach for asymmetric syntheses of (+)-spicigerine, (+)-cassine and their 3-epimers

作者：Han, Pan; Si, Chang-Mei; Mao, Zhuo-Ya; Li, Hai -Tong; Wei, Bang-Guo; Du, Zhen-Ting^*

来源：Tetrahedron, 2016, 72(6): 862-867.

DOI：10.1016/j.tet.2015.12.057

• Total synthesis
• Spicigerine
• Cassine
• Tandem process
• Chiral aldimine

An efficient approach for asymmetric synthesis of (+)-spicigerine, (+)-cassine and their 3-epimers has been developed through the intramolecular diastereoselective tandem addition/cyclisation process of alpha-chiral aldimine 9 with methylmagnesium bromide and the asymmetric addition of nucleophilic reagents to aminal 14. Moreover, the first asymmetric synthesis of (+)-spicigerine has been achieved in this manuscript. In this synthetic strategy, the asymmetric syntheses of (+)-spicigerine and (+)-cassine was achieved in a 14% overall yield and nine steps and an 18% overall yield and seven steps from cheap a chiral aldimine 9, respectively.

• 出版日期2016-2-11
• 单位西北农林科技大学; 复旦大学