TOTAL SYNTHESIS OF THE POTENT ANTITUMOR, BIS-TETRAHYDROFURANYL ANNONACEOUS ACETOGENINS (+)-ASIMICIN AND (+)-BULLATACIN

Convergent syntheses of the title compounds involve: a bis-THF-subunit preparation via Sharpless' double asymmetric dihydroxylation and subsequent asymmetric epoxidation; preparation of the C(4)-hydroxybutenolide-containing subunit using a Stille butenolide synthesis, Pd degrees-mediated coupling of these vinyl iodide and alkyne subunits; and selective Wilkinson reduction of the resulting enyne.