Toward the Total Synthesis of Eurifoloid A.

Construction of the [5-7-7] tricyclic core of eurifoloid A, which contains an unusual and highly strained bicyclo[4.4.1]undecane ring system with trans-bridgehead, was attempted using a type II intramolecular [5 + 2] cycloaddition reaction and a Meinwald rearrangement reaction of the epoxide as key synthetic steps. The reported chemistry illustrates the feasibility of constructing the 8-epi-eurifoloid A framework by type II intramolecular [5 + 2] cycloaddition.