Total synthesis of the antitumor natural product Polycarcin V

Polycarcin V is a member of the gilvocarcin family that is naturally produced from Streptomyces polyformus. It has shown to have selective cytotoxicity to non-small-cell lung cancer, breast cancer, and melanoma cells. In order to analyze the interaction of this natural substance and its other family members with sequential specificity to duplex DNA, we undertook the convergent total synthesis of Polycarcin V in 4.6% overall yield from three major fragments of suitably protected rhamnosyl diacetate, aromatic naphthol and regioselectively iodinated carboxylic acid; the synthesis also demonstrates a stereoselective α-C-glycosylation reaction for the assembly of the structurally unique rhamnose sugar and the selectively methylated aromatic naphthol.