was chromatographed on silica gel or on basic alumina to
afford the products.
Table 3 Synthesis of b-enamino esters and b-enaminonesa
Entry
1
Product
Yield (%)
90
Acknowledgements
This work was supported by a grant (20272049) from National
Natural Science Foundation of China. We would like to thank
the International Cooperation Division of Yunnan Provincial
Science & Technology Department for partial financial support
(2002GH04).
2
3
4
92
92
94
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5
99
a
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´ ´
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5
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9
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Scheme 2 Synthetic approach towards the indolizidine ring system.
N e w J . C h e m . , 2 0 0 5 , 2 9 , 7 6 9 – 7 7 2
771