Here we report a general [3 + 2] radical annulation that allows the facile construction of bicyclo[3.2.1]octane motifs in ent-kaurane- and beyerane-type diterpenoids. This radical annulation is difficult to control but was realized by harnessing an unprecedented and counterintuitive effect of TEMPO. Eleven natural products with a wide array of oxidation states are easily prepared, demonstrating the
在这里,我们报告了一个通用的 [3 + 2] 自由基环化,它允许在ent -kaurane- 和 beyerane 型二萜中轻松构建双环 [3.2.1]
辛烷基序。这种激进的环化很难控制,但通过利用
TEMPO 前所未有的和违反直觉的效果来实现。11 种具有多种氧化态的
天然产物很容易制备,证明了这种简单合成策略的强大效用。