Palladium‐Catalyzed Three‐Component Reaction of Enol Ethers, Salicylaldehyde, and Trimethyl Orthoformate: A Fast Synthesis of Tetrahydro‐2H,5H‐Pyrano[2,3‐b]Chromenes

ABSTRACT The Pd‐catalyzed three‐component reaction of enol ethers, methyl orthoformate, and salicylaldehyde is described. Both steroid and non‐steroid enol ethers are compatible. This reaction allows the construction of tetrahydro‐2H,5H‐pyrano[2,3‐b]chromene. Unambiguous NMR characterization and X‐ray diffraction structures are provided.