Rapid and Stereoselective Synthesis of Spirocyclic Ethers via the Intramolecular Piancatelli Rearrangement

The first example of a Piancatelli rearrangement of alcohols is demonstrated utilizing dysprosium(III) trif late as a catalyst to access oxaspirocycles in a highly diastereoselective manner. The cascade reaction constructs the spirocyclic ether ring system and the tertiary stereocenter in a single operation and is experimentally easy to perform.