Palladium-Catalyzed Medium-Ring Formation for Construction of the Core Structure of Laurencia Oxacycles: Synthetic Study of Laurendecumallene B

Palladium-catalyzed medium-ring formation from a cyclic propargyl carbonate via a ring-opening and -closing cascade proceeded at the central carbon atom of the propargyl unit to provide a tetrahydro-2H-oxocine derivative bearing the core structure of laurencia oxacycle. The synthetic application of this reaction to a possible laurendecumallene B precursor is also presented.