| The stereoselective construction of ether bonds has become an increasingly important synthetic transformation, particularly in the context of cyclic ethers. The selective preparation of these structural motifs has remained at the forefront of methodology development due to their presence in a vast number of both structurally challenging and biologically important natural products. We have developed a stereodivergent method for the synthesis of cyclic ethers via a regioselective and enantiospecific rhodium-catalyzed allylic etherification using copper(I) alkoxides. We have also reported a novel diastereoselective intramolecular bismuth-mediated oxa-conjugate addition reaction for the synthesis of cis -2,6-disubstituted tetrahydropyrans. The scope and limitations of these transformations were examined, and they were utilized in the syntheses of the biologically important natural products, gaur acid and leucascandrolide A respectfully. |
