combretastatins D-2 and D-4 as well as a formal synthesis of combretastatin D-1 by a conceptually new route harnessing a ring-contracting flash vacuum pyrolytic extrusion of sulfur dioxide from the respective 16-membered sulfone precursors. Via flash vacuum pyrolysis, even metaparacyclophanes as small and strained as the hitherto unknown oxa[1.5]metaparacyclophane could be prepared as a side product en
我们报告了康布雷他汀D-2和D-4的合成,以及康布雷他汀D-1的正式合成,其方法是利用从相应的16元砜前体中环氧化的快速真空热解法挤出
二氧化硫的概念新方法。通过快速真空热解,甚至可以通过同步挤出SO 2和CO 2,制备出与迄今未知的oxa [1.5] metaparaparaphanphane一样小且应变过大的metaparacyclophanes作为副产物,以通向combretastatin D- 2。