Macrocyclic natural products olefin ring-closing metathesis

In the ring-closing metathesis reaction (RCM), a diene is allowed to undergo intramolecular olefin metathesis to give a cyclic alkene and ethylene the latter is removed to drive the equilibrium forward. The RCM has quickly been adopted as a premier method for preparing macrocyclic natural products. 

The epothilones comprise an important set of natural products that were discovered at a time contemporary with the development of ring-closing olefin metathesis. These materials are 16-membered ring compounds containing an alkene in the macrocycle or an epoxide that can be generated from the alkene. A conventional retrosyntlietic analysis... 

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