The Spongistatins: Architecturally Complex Natural Products-Part One: A Formal Synthesis of (+)-Spongistatin 1 by Construction of an Advanced ABCD Fragment Financial support was provided by the National Institutes of Health (National Cancer Institute) through Grant CA-70329, NIH Postdoctoral Fellowships to A.M.B. and W.H.M., a Japan Society for Promotion of Science Fellowship to N.M., and a Royal Society Fulbright Fellowship to V.A.D. We also thank the Daiichi Pharmaceutical Co., Ltd, and the Tanabe Seiyaku Co., Ltd for financial support. Finally we thank Dr. George T. Furst, Dr. Patrick J. Carroll, Dr. Rakesh Kohli, and Mr John Dykins of the University of Pennsylvania Spectroscopic Service Center for assistance in securing and interpreting high-field NMR spectra, X-ray crystal structures, and mass spectra.