Attempted [2]Catenane Synthesis via a Quasi[1]catenane by a Templated Backfolding Strategy

A templated backfolding concept to construct a [2]catenane was attempted via a quasi[1]catenane showing an inverted spiro geometry. The template is covalently connected to the ketal-connected semi-perpendicular-arranged linear precursors and spatially directs the sterically congested backfolding macrocyclizations that are required to give a quasi[1]catenane. So far, we are unable to hydrolyze the cyclic ketal to liberate the [2]catenane.