Synthesis of oxa-bridged carbocycles via rhodium/Lewis acid catalyzed [3 + 3] and [4 + 3] cycloadditions of carbonyl ylides with donor–acceptor strained carbocycles

A method for cooperative rhodium/Lewis acid-catalyzed cycloadditions of carbonyl ylides with donor–acceptor (D–A) strained carbocycles is described. It affords structurally diverse oxa-bridged carbocycles with high efficiency and stereoselectivity.