Lewis Acid Catalyzed Formal Intramolecular [3 + 3]Cross-Cycloaddition of Cyclopropane 1,1-Diesters for Constructionof Benzobicyclo[2.2.2]octane Skeletons.

A novel Lewis acid catalyzed formalintramolecular [3 + 3] cross-cycloaddition(IMCC) of cyclopropane 1,1-diesters has been successfully developed.This supplies an efficient and conceptually new strategy for constructionof bridged bicyclo[2.2.2]octane skeletons. This [3 + 3]IMCC couldbe run up to gram scale and from easily prepared starting materials.This [3 + 3]IMCC, together with our previously reported [3 + 2]IMCCstrategy, can afford either the bicyclo[2.2.2]octane or bicyclo[3.2.1]octaneskeletons from the similar starting materials by regulating the substituentson vinyl group. [ABSTRACT FROM AUTHOR]