The cisoid‐selective construction of a tricyclic bisspiroacetal framework was demonstrated using MgBr₂ as a cisoid stabilizer through chelation of the oxygen atoms of lateral acetal rings in the cisoid configuration. The method was also successfully applied to substrates with different ring sizes and substituents. Thus, this method serves as a useful synthetic strategy for the total synthesis of bisspiroacetal‐containing natural products.

中文翻译：

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通过双侧乙缩醛氧原子的镁配位的立体选择双螺缩醛框架的立体选择。

通过使用MgBr ₂作为顺式稳定剂，通过在顺式构型中将侧缩醛环的氧原子螯合，证明了三环双螺缩醛骨架的顺式选择性构建。该方法也成功地应用于具有不同环尺寸和取代基的底物。因此，该方法为全合成含双螺缩醛的天然产物提供了有用的合成策略。