A Formal Total Synthesis of ( )-Pinnatoxin AThis work was supported by CREST, Japan Science and Technology Agency (JST). A fellowship to H.S. from the Japan Society for the Promotion of Science (JSPS) is gratefully acknowledged. We thank Professor Y. Kishi (Harvard University) for providing NMR spectra of synthetic intermediates, Professor D. Uemura (Nagoya University) for providing natural pinnatoxin A, and Professor K. Nagasawa (Tokyo University of Agriculture and Technology) for helpful discussions.