Straightforward Synthesis of Spirocyclic Tetrahydrofurans by a Reductive MCR/Iodoetherification Sequence

A straightforward and modular sequence for the synthesis of substituted spirocyclic tetrahydrofurans is described. The strategy relies on a reductive cobalt-catalyzed three-component reaction between a cyclic ketone, an acrylate, and a vinylic bromide followed by an intramolecular iodoetherification of the resulting γ-hydroxyalkene. Some functional group interconversions allowed the preparation of more varied spirocyclic compounds.