The Absolute Configuration and Asymmetric Total Synthesis of the CP Molecules (CP-263,114 and CP-225,917, Phomoidrides B and A) We thank Drs. D. H. Huang, G. Siuzdak, and R. Chadha for assistance with NMR spectroscopy, mass spectrometry, and X-ray crystallography, respectively. This work was financially supported by the National Institutes of Health (USA), The Skaggs Institute for Chemical Biology, doctoral fellowships from the National Science Foundation (P.S.B.) and Boehringer Ingelheim (Y.H.), and grants from Array Biopharma, Boehringer Ingelheim, Schering Plough, Pfizer, Glaxo, Merck, Hoffmann-La Roche, DuPont, and Abbott Laboratories.