Total Synthesis of Bioactive peri-Hydroxyquinone Natural Products

Isolated from a cyanobacterium genus Eucapsis, eucapsitrione exhibits promising antitubercular activity; however, anomalies in its spectroscopic data cast doubt upon the assignment of its fused indeno-anthraquinone structure. The antimalarial natural product albopunctatone was isolated from a Great Barrier Reef ascidian, and possesses an anthrone-anthraquinone backbone, which had not been synthesised previously. The plant-derived binaphthoquinone diospyrin has recently been reported to inhibit Mycobacterium tuberculosis DNA gyrase by a novel mechanism of action. The bioactivity of the unnatural diospyrin isomer, idospyrin, has not been explored. Total syntheses of these compounds are described.