Silver(I)-Catalyzed Addition of Zirconocenes to Epoxy Esters:  A New Entry to 1,4-Dicarbonyl Compounds and Pyridazinones

The Ag(I)-catalyzed tandem epoxy ester rearrangement−dioxycarbenium ion addition reaction with alkenyl zirconocenes provides 1,4-keto esters that can be further converted to substituted pyridazinones. The use of a fluorous tag in a cyclization-assisted cleavage strategy demonstrates the feasibility of extending this methodology to high-throughput organic synthesis.