Concise Synthesis of Cyclic Ethers via the Palladium-Catalyzed Coupling of Ketene Acetal Triflates and Organozinc Reagents. Application to the Iterative Synthesis of Polycyclic Ethers
作者:Isao Kadota、Hiroyoshi Takamura、Kumi Sato、Yoshinori Yamamoto
DOI:10.1021/jo025566f
日期:2002.5.1
The reaction of the ketene acetal triflates 9a-e and a zinc homoenolate 10 in the presence of a catalytic amount of Pd(PPh(3))(4) gave the enol ethers 11a-e in good yields. The products were converted to the corresponding cyclic ethers 14a and 14b by hydroboration and lactonization. The present methodology allowed us to synthesize the DE and GH ring segment of gambierol in a concise manner. Iterative
在催化量的Pd(PPh(3))(4)存在下,乙烯酮缩醛三氟甲磺酸酯9a-e和均烯酸锌10的反应以良好的产率得到烯醇醚11a-e。通过硼氢化和内酯化将产物转化为相应的环醚14a和14b。本方法学使我们能够以简明的方式合成甘比罗尔的DE和GH环段。还描述了多环醚26和32的迭代合成。