Synthesis of stemofurans C, L and T using organomanganese arene chemistry; revised structure for stemofuran L

The synthesis of stemofurans C, L and T was achieved using organomanganese arene complexes. The critical carbon-carbon bond between the C-2 position of benzofuran and the arene was established in a regioselective manner directed by the cationic manganese tricarbonyl moiety. Oxidation of the resulting dienyl complexes and cleavage of the methyl ethers gave the desired stemofuran products. The spectroscopic data for the originally proposed structure for stemofuran L did not match the synthesized material, which prompted the synthesis of an isomer that did match the spectroscopic data. This revised structure has been proposed as the correct structure for stemofuran L.