Exploration of Ring Rearrangement Metathesis Reaction: A General and Flexible Approach for the Rapid Construction [5,<i>n</i>]‑Fused Bicyclic Systems en Route to Linear Triquinanes

Structurally diverse [5,n] bicyclic systems with cis ring junction stereochemistry were accessed readily through RRM (ring rearrangement metathesis) reaction of properly functionalized [2.2.1]­norbornene skeletons. Several bicyclic enones, ketones, alcohols, and ethers acted as the substrates and yielded the respective linearly fused [5,n] bicyclic systems stereoselectively after the RRM reaction. Such [5,5]­bicyclic enone scaffolds were then synthetically manipulated to core structural analogue of naturally occurring liner triquinane hirsutene having cis-syn-cis stereochemistry.