TOTAL SYNTHESIS OF BACCATIN-III AND TAXOL

An intramolecular Heck reaction (90 --> 91) serves as the key step in the total synthesis of the titled compounds. The synthetic route is ba sed on utilizing the Wieland-Miescher ketone (5) as a matrix to provid e the C and D rings of the targets and to provide functionality implem ents for joining this sector to an A ring precursor (6). Catalytically induced enantiotopic control and early emplacement of the oxetane are other features of the route.