A formal total synthesis of (-)-taxol by a convergent approach utilizing Pd-catalyzed intramolecular alkenylation is described. Formation of the eight-membered carbocyclic ring has been a problem in the convergent total synthesis of taxol but it was solved by the Pd-catalyzed intramolecular alkenylation of a methyl ketone affording the cyclized product in excellent yield (97 %), indicating the high efficiency of the Pd-catalyzed intramolecular alkenylation. Rearrangement of the epoxy benzyl ether through a 1,5-hydride shift, generating the C3 stereogenic center and subsequently forming the C1-C2 benzylidene, was discovered and utilized in the preparation of a substrate for the Pd-catalyzed reaction.

A new method for synthesizing polyalkylated/arylated nicotinates is established using a condensation of enamino esters with enones in the presence of FeCl. This method facilitates the introduction of alkyl or aryl groups at any position on demand, which has not been achieved by other procedures.

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Formal total synthesis of ( ) taxol is described herein. This convergent synthesis was accomplished by utilizing two chiral fragments, both of which were prepared via asymmetric catalysis. A palladium catalyzed reaction was found to afford the eight membered ring effectively, i.e., a B alkyl Suzuki Miyaura coupling reaction and an intramolecular alkenylation of a methyl ketone successfully constructed the B ring of taxol in excellent yield. During the preparation of a substrate for the palladium catalyzed reaction, a unique rearrangement of the epoxy benzyl ether, via a 1,5 hydride shift that generates the C3 stereogenic center and subsequently forms the C1 C2 benzylidene moiety, was observed. Strenuous efforts were required for transformations after the construction of the taxane scaffold to achieve the formal total synthesis of taxol because very few approaches are available for the synthesis of the target compound.

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