Electrophile‐Promoted Tandem Cyclization of α,β‐Diynyl Ketodiols: A Facile Synthesis of Tetrahalogenated Spiroketals

An efficient synthetic approach to tetrahalogenated spiroketals has been developed through a tandem iodocyclization of various alpha,beta-diynyl ketodiols. The diastereoselective construction of a chiral spiroketal center induced by the chiral alkynol functional groups is possible. The obtained tetrahalogenated spiroketals can be applied in subsequent palladium-catalyzed coupling reactions to produce compounds with multiple aromatic substituents.