Asymmetric synthesis of epohelmins A, B and 3-epi ent-epohelmin A

作者：Si, Chang-Mei; Liu, Yi-Wen; Mao, Zhuo-Ya; Han, Pan; Du, Zhen-Ting; Wei, Bang-Guo^*

来源：Tetrahedron, 2016, 72(49): 8091-8098.

DOI：10.1016/j.tet.2016.10.047

• Asymmetric synthesis
• Natural product
• Cross-coupling
• Epohelmins
• Cascade cyclization

An efficient method for asymmetric synthesis of epohelmins A (3), B (4) and their isomer 24 is detailed in this report. The key feature in this divergent synthesis includes the Sml(2)-induced cross-coupling of N-tert-butanesulfinyl imine 10 with chiral aldehyde 9 derived from D-malic acid. A cascade cyclization to the pyrrolizidine skeleton is achieved in our synthetic route for epohelmins. In addition, an interesting intramolecular oxa-Michael addition was observed for epohelmin A (3).

• 出版日期2016-12-8
• 单位西北农林科技大学; 复旦大学