Synthesis of propellanes containing a bicyclo[2.2.2]octene unit via the Diels–Alder reaction and ring-closing metathesis as key steps

The synthesis of propellanes containing bicyclo[2.2.2]octene via olefin metathesis approach is less explored. Herein, we describe a simple and convenient method to synthesize propellane derivatives containing a bicyclo[2.2.2]octene unit which are structurally similar to 11β-HSD1 inhibitors by sequential usage of the Diels–Alder reaction, C-allylation and ring-closing metathesis (RCM) as the key steps. Additionally, we expanded this approach to an endo-tricyclo[4.2.2.0(2,5)]decene derivative which is a useful monomer for polymer synthesis and we have also synthesized basketene and anthracene-based propellanes using the same strategy.