Towards the Synthesis of Paulitin: New Insights into the EnyneMetathesis Mechanism

In our approach towards Paulitin, a sesquiterpene lactone, we have shown that steric hindrance at the propargylic position is of importance to the outcome of enyne metathesis. Moreover, we have uncovered further evidence to confirm that the alkyne-first pathway should be the favored process in enyne metathesis.