Enantioselective Rhodium-Catalyzed Dimerization of ω-Allenyl Carboxylic Acids: Straightforward Synthesis of C2-Symmetric Macrodiolides

Herein, we report on the first enantioselective and atom-efficient catalytic one-step dimerization method to selectively transform omega-allenyl carboxylic acids into C-2-symmetric 14 to 28-membered bismacrolactones (macrodiolides). This convenient asymmetric access serves as an attractive route towards multiple naturally occuring homodimeric macrocyclic scaffolds and demonstrates excellent efficiency to construct the complex, symmetric core structures. By utilizing a rhodium catalyst with a modified chiral cycloperaylidene-diop ligand, the desired diolides were obtained in good to high yields; high diastereoselectivity, and excellent enantioselectivity