In our synthetic studies toward huperzine A, a diastereoselective α′-alkylation of the α-amido-γ-methyl hexenone 4 was realized through a dianion intermediate which significantly enhanced the reactivity. Under the attempted Heck reaction conditions, an unexpected and unprecedented palladium-catalyzed intramolecular γ-arylation of 3 was observed, which generated 18 with bicyclo[3.3.1]nonane framework in satisfactory yield.
在我们对胡朴素 A 的合成研究中,α-酰胺基-γ-甲基己烯酮 4 的非对映选择性 α′-烷基化是通过二离子中间体实现的,这显著提高了反应活性。在尝试的 Heck 反应条件下,观察到 3 发生了意想不到的、前所未有的
钯催化分子内 γ-芳基化反应,生成了具有双环[3.3.1]
壬烷框架的 18,产率令人满意。