Enantiospecific Total Synthesis of (+)-3-epi-Epohelmin A Using a Nitrogen-Substituted Donor-Acceptor Cyclopropane
Enantiospecific Total Synthesis of (+)-3-epi-Epohelmin A Using a Nitrogen-Substituted Donor-Acceptor Cyclopropane
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DOI：
10.1002/ejoc.201700498
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发表时间：
2017-07-25
影响因子：
2.8
通讯作者：
Kumari, Dimple
中科院分区：
文献类型：
--
作者：
Gharpure, Santosh J.;Nanda, Laxmi Narayan;Kumari, Dimple
以对映体纯的L-吡咯谷氨酸为起始原料，通过快速构建吡咯里西啶核，实现了（+）-3-epi-epohelmin的对映体特异性全合成。关键反应包括高度区域和立体选择性的分子内环丙烷化反应，区域选择性开环的氮取代的供体-受体环丙烷，立体选择性还原酮，化学选择性有机锂加成到Weinreb酰胺，和化学选择性氧化烯丙醇。
The enantiospecific total synthesis of (+)-3-epi-epohelmin was accomplished by rapid construction of the pyrrolizidine core starting from enantiopure L-pyrroglutamic acid. The key reaction included a highly regio-and stereoselective intramolecular cyclopropanation reaction, regioselective ring opening of a nitrogen-substituted donor-acceptor cyclopropane, stereoselective reduction of a ketone, chemoselective organolithium addition to a Weinreb amide, and chemoselective oxidation of an allylic alcohol.