An Approach Toward the Bridged 14‐Membered Carbon Macrocycle of Bielschowskysin

Relying on our previous achievements toward the a total synthesis of bielschowskysin,1-5 we herein report additional efforts to close the bridged tetradecane carbocyclic core of this marine diterpene. The key step of this strategy is an intramolecular alkylation between a cis-substituted vinyl halide and a lactone that were accessed by a diastereoselective propargylation/hydrogenation sequence and palladium-catalyzed carbonylation, respectively.