Total synthesis of moniliformediquinone and calanquinone A as potent inhibitors for breast cancer

The first synthesis of moniliformediquinone has been achieved in which the longest linear sequence is only nine steps. The synthesis proceeds in 23% overall yield from commercially available 2,4,5-trimethoxybenzaldehyde. The key transformations include a Pd-catalyzed coupling between a phenyl triflate and an acetylene, and a TiCl4-mediated cyclization of a benzoquinone intermediate. In addition, in vitro inhibitory effects of moniliformediquinone, denbinobin, moscatilin, and calanquinone A were determined to have IC50 values of 0.7, 1.6, 2.5, and 1.5 μM, respectively.