Catalytic asymmetric synthesis of either enantiomer of the Calabar alkaloids physostigmine and physovenine

被引:234
作者
Matsuura, T [1 ]
Overman, LE [1 ]
Poon, DJ [1 ]
机构
[1] Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA
关键词
D O I
10.1021/ja980788+
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
A potentially versatile asymmetric route to hexahydropyrrolo[2,3-b]indoles having carbon substituents at C-3a (Scheme 1) is demonstrated through enantioselective total syntheses of the Calabar alkaloids.(-)-physostigmine (2), (-)-physovenine (10), and their enantiomers. The synthesis of enantiopure (-)physostigmine proceeds from commercially available 2-butyn-1-ol (11) and N-methyl-p-anisidine (15) in 15-20% overall yield by way of eight isolated and purified intermediates. The central step is catalytic asymmetric Heck cyclization of (Z)-2-methyl-2-butenanilide 17 to form oxindole aldehyde (S)-19 in 84% yield and 95% ee.
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页码:6500 / 6503
页数:4
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