Herein, we report the application of tandem ring‐opening cross‐metathesis (ROCM) and tandem ring‐opening cross‐metathesis followed by cross‐metathesis (ROCM/CM) in highly strained diastereomeric heptacyclic cage diones (HCCD's) catalyzed by ruthenium catalysts. These caged diastereomeric compounds have a high degree of ring strain as well as steric congestion. Therefore, the present work related to ROCM is unique and intricate as compared to simple norbornene derivatives. It is useful to prepare new hexacyclic cage derivatives suitable for high‐energy density materials. The synthetic strategy of starting cage compounds features the Diels‐Alder reaction, and [2+2] photocycloaddition as key steps.

We report late-stage ring-opening metathesis (ROM), ring-rearrangement metathesis (RRM), and ring-closing metathesis (RCM) approaches to generate expanded pentacycloundecane (PCUD) cage derivatives. These higher-order intricate polycyclic cage systems are aesthetically pleasing and structurally intriguing. Their assembly maintains molecular symmetry during the entire synthetic sequence. To this end, metathesis-based catalysts are used to execute the ROM, RRM, and RCM strategies. The synthetic approach to these cage polycycles involves the Diels−Alder reaction, [2 + 2] photocycloaddition, RRM, ROM, and RCM as key steps.

Herein, we report strain-driven regioselective tandem ring-opening cross-metathesis (ROCM) of a linearly fused cage system that contains both bicyclo[2.2.1]heptene and bicyclo[2.2.2]octene units fused to the same cage system. The synthesis of novel cage propellane involves the Diels-Alder cycloaddition and [2+2] photocycloaddition as key steps.