Eschenmoser烯化反应

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中性加热条件下吖丙啶基腙通过重氮中间体消除制备烯烃反应。产物为更多取代基的烯烃。利用BuLi作碱可以在低温下进行【J Am Chem Soc.1980, 102, 774】。此反应可以制备 Bamford-Stevens反应和Shapiro反应不能得到的三取代烯烃【Tet Lett.1984, 25, 271】。


Rh2(OAc)4催化下,α-烯丙氧基酮腙通过Rh配位卡宾中间体得到Z-烯基烯丙氧醚,接着进行Claisen重排得到反式二取代γ-不饱和酮或醛。【J Am Chem Soc.2002, 124, 12426】(7少画了一个苯基,感谢葛树升指正)


反应操作

anti 2,3-Diphenyl-4-pentenal (10). To a Schlenk tube with Rh2(OAc)4 (2.5 mg, 0.0057 mmol) underN2 was added DCE (3 mL) and hydrazone 7 (101.9 mg, 0.277 mmol). The tube was sealed and the mixture was stirred at 130 ℃ till completion (TLC 18:1, pentane-ether) and passed through a silica pad and evaporated in vacuo. Flash chromatography (25:1, pentane-ether) gave 57 mg, 87% of 10, mp 101–103.5 ℃ (from pentane).

J Am Chem Soc., 2002, 124, 12426



相关文献

1 Eschenmoser A Helv Chim Acta 1972 55 1276

2 Eschenmoser A Org Syn 1976 55 114

3 Evans DA J Am Chem Soc 1980 102 774

4 Collum DB Tet Lett 1984 25 271

5 Kirmse W Eur J Org Chem 1998 1 201

6 Stolz BM J Am Chem Soc 2002 124 12426


编译自:Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, 141-142.


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