Asymmetric Synthesis of Phorboxazole B-Part I: Synthesis of the C(20)-C(38) and C(39)-C(46) Subunits Financial support was provided by the National Institutes of Health (GM-33328) and the National Science Foundation. An American Cancer Society Postdoctoral Fellowship to T.E.S. and an NSF Predoctoral Fellowship to V.J.C. are gratefully acknowledged. The NIH BRS Shared Instrumentation Grant Program 1-S10-RR04870 and the NSF (CHE 88-14019) are acknowledged for providing NMR facilities.