Tricarbocyclic fused systems

An approach to the synthesis of a linearly fused 6-8-6 tricarbocyclic ring system was realized by the use of dienyne metathesis (Scheme 24.53). " This ring system is a carbon analog for the proposed transition state of the... 

Illustrating the high potential of these reactions, cascade ring-closing metathesis of dienynes or trienynes have also provided access to fused 6,8,6-tricarbocyclic systems [14], and to a highly functionalized 5,7,6-tricyclic ring system related to the terpenoid guanacastepene A structure [15]. 

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