Molecules (May 2016)
Total Synthesis and Antifungal Activity of Palmarumycin CP17 and Its Methoxy Analogues
Abstract
Total synthesis of naturally occurring spirobisnaphthalene palmarumycin CP17 and its methoxy analogues was first achieved through Friedel-Crafts acylation, Wolff-Kishner reduction, intramolecular cyclization, ketalization, benzylic oxidation, and demethylation using the inexpensive and readily available methoxybenzene, 1,2-dimethoxybenzene and 1,4-dimethoxybenzene and 1,8-dihydroxynaphthalene as raw materials. Demethylation with (CH3)3SiI at ambient temperature resulted in ring A aromatization and acetal cleavage to give rise to binaphthyl ethers. The antifungal activities of these spirobisnaphthalene derivatives were evaluated, and the results revealed that 5 and 9b exhibit EC50 values of 9.34 µg/mL and 12.35 µg/mL, respectively, against P. piricola.
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