摘要:
The first asymmetric syntheses of four members of the abyssinone class of natural products (I, II, III, and IV 4'-OMe) via quinine- or quinidine-derived thiourea-catalyzed intramolecular conjugate additions of beta-keto ester alkylidenes are reported. This concise strategy delivers all four natural products and their corresponding antipodes. A preliminary evaluation of all of these small molecules against a metastatic human prostate cancer cell line has identified that these compounds selectively and differentially inhibit cell growth and downregulate the expression of matrix metalloproteinase-2 (MMP-2) at nontoxic concentrations.