Regiocontrolled construction of furo[3,2-c]pyran-4-one derivatives by palladium-catalyzed cyclization of propargylic carbonates with 4-hydroxy-2-pyrones.

The reaction of propargylic carbonates with 4-hydroxy-2-pyrones in the presence of a palladium catalyst is described. By the choice of the reaction temperature, two types of the substituted furo[3,2-c]pyran-4-one derivatives were regioselectively synthesized, respectively.