The Spongistatins: Architecturally Complex Natural Products-Part Two: Synthesis of the C(29-51) Subunit, Fragment Assembly, and Final Elaboration to (+)-Spongistatin 2 Financial support was provided by the National Institutes of Health (National Cancer Institute) through Grant CA-70329, a NIH Postdoctoral Fellowship to C.S.B., 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, and Dr. Rakesh Kohli 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, respectively.