An attempt to construct the C/D ring system of parkacine by intramolecular cycloaddition of azomethine ylide and alkyne

Zhang Wenxuan Wang Jiming Luo Xihuan Meng Xiangbao Li Zhongjun · 2016

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亚胺叶立德

期刊名称：

Tetrahedron Letters 2016 年 57 卷 18 期

发表日期：

2016.05.04

摘要：

Intramolecular 1,3-dipolar cycloaddition of chiral hept-6-yne-azomethine ylide was attempted to construct the C/D ring system of a lycorine-type alkaloid parkacine (3). However, the cycloaddition reactions gave C/D ring-closure product with opposite configurations at 7- and 7a-carbons, comparing with the natural product. The unexpected epimerization of phenyl substituted chiral carbon may occur through imine-enamine tautomerism before the intramolecular cycloaddition.