Intermolecular Additions and Cycloisomerizations by a Pd‐Catalyzed Sequence of an Intramolecular Redox Reaction and an Addition

Unusual chemoselectivity is found in the novel reaction sequence catalyzed by the palladium complex 3 by which propargyl acetates 1 are smoothly converted into synthetically interesting geminal diacetates 2. Even when the R group contains double bonds, hydroxyl, or carbonyl groups, 2 is formed exclusively in excellent yields. Macrolides can also be prepared by this method, dba = Dibenzylidenacetone.