Cyclic peptides isolated from tunicates have captured wide scientific attention from both a drug discovery and ecological perspective. For these reasons cyclic peptides have witnessed considerable synthetic attention, especially those containing azoles. Further pursued herein is the application of the heteroatom interchange (HI) concept to cyclic peptides, in particular ascidiacyclamide. In the HI‐ascidiacyclamide case, the nitrogen and sulfur atoms of both thiazole rings have been transposed through the incorporation of thiazole‐5‐carboxamide units rather than the native thiazole‐4‐carboxamides. Presented herein are the synthesis of an HI‐ascidiacyclamide isomer, a molecular‐mechanics study of its three‐dimensional structure, and a mass spectrometric and density functional theory study of its copper‐binding properties.