(Table , a). For the second step of this one-pot reaction, the oxidation (b) and cyclization (c) sequence with the most prominent oxidants (see Table , Supporting Information (SI)) were screened. We were able to establish Selectfluor ® as the most effective oxidant. It was the only oxidant that resulted in quantitative oxidation of the intermediate 5a to 6a. A quantitative transformation was necessary since an incomplete oxidation resulted in the undesired formation of acyclic iodonium salts due to the electron-donating character of diphenylether motifs.