Ring‐Rearrangement Metathesis Approach to Fused [5/5/6/5/5] and [6/5/5/5/5/6] Carbocyclic Derivatives.

Here, we have developed a simple synthetic approach towards synthesis of [5/6/5] and [5/5/5] fused carbocyclic frameworks from bis‐adducts of norbornadiene and cyclohexadiene derivatives with 1,2,3,4‐tetrachloro‐5,5‐dimethoxycyclopentadiene by employing atom‐economic ring‐rearrangement metathesis as a key step and these ring systems are core units in natural products. Here, we have designed highly congested polycyclic frameworks and introduced molecular complexity in a minimum number of steps. These targets contain up to seven stereo centres. Hence, this strategy can be used to design many different drug‐like molecules valuable in medicinal chemistry. [ABSTRACT FROM AUTHOR]