School of Chemistry, University of Manchester, Manchester, United Kingdom.
J Am Chem Soc. 2012 Aug 1;134(30):12751-7. doi: 10.1021/ja3047975. Epub 2012 Jul 18.
Unsaturated lactones undergo reductive radical cyclizations upon treatment with SmI(2)-H(2)O to give decorated cycloheptanes in a single highly selective operation during which up to three contiguous stereocenters are generated. Furthermore, cascade processes involving lactones bearing two alkenes, an alkene and an alkyne, or an allene and an alkene allow "one-pot" access to biologically significant molecular scaffolds with the construction of up to four contiguous stereocenters. The cyclizations proceed by the trapping of radical anions formed by electron transfer reduction of the lactone carbonyl.
不饱和内酯在 SmI(2)-H(2)O 作用下发生还原自由基环化反应，在单一高选择性操作中生成装饰性的环庚烷，在此过程中可生成多达三个连续的立体中心。此外，涉及带有两个烯烃、一个烯烃和一个炔烃或一个丙二烯和一个烯烃的内酯的级联过程允许“一锅法”获得具有多达四个连续立体中心的构建的生物重要分子支架。环化反应通过内酯羰基的电子转移还原形成的自由基阴离子的捕获进行。
