Peptide isosteres are important tools for the understanding of peptide function and for the development of drugs. (E)-Alkene peptide isosteres are particularly useful due to their close geometric match of the amide bond structure. We developed a method for the generation of a small library of (E)-alkene peptide isosteres on solid support via cuprate mediated SN2' ring opening of allylic BUS-aziridines. We also studied the selectivity for the opening of these aziridines in the solution phase.;Halenaquinone is a marine natural product that was first isolated in 1983 from the Pacific sponge Xestosongia exigua. We realized the synthesis of a thiophene-containing analog, thio-halenaquinone. The key steps include an alkynyl ketone-benzocylcobutane Diels-Alder reaction to construct the naphthalene subunit, a Heck cyclization to form the quaternary carbon, and a ring closing metathesis to install the final ring. This compound showed an IC90 ∼5 muM against Pfnek-1 and an analog that had an IC90 ∼3 muM. Based on these results we designed and synthesized a simplified analog that showed an IC90 ∼4 muM. This compound was selected to move on to animal testing and the synthesis was optimized for the preparation of and 200 mg of the lead structure.