Modular Synthesis of [6,6]‐Oxaspirolactones Enabled by Palladium‐Catalyzed Carbonylative Spirolactonization

An expedient and efficient carbonylative protocol proceeded via palladium‐catalyzed tandem cyclic ketonization and carbonylative spirolactonization has been developed. This carbonylation reaction is compatible with a wide range of hydroxyalkyl ketone tethered benzyl chlorides bearing different functional groups and can be proceeded under comericially available Pd 2 (dba) 3 /BINAP catalyst system, providing a straithfowrd and practical approach to a broad range of [6,6]‐oxaspirolactones. The synthesized [6,6]‐oxaspirolactones are commonly found as core structures in natural products and can potentially serve as C 2 ‐symmetric ligand synthons.