A Convergent Total Synthesis of Ustiloxin D via an Unprecedented Copper-Catalyzed Ethynyl Aziridine Ring-Opening by Phenol Derivatives

[reaction: see text] The ustiloxins are a family of heterodetic cyclopeptides that have been isolated from the water extracts of false smut balls on the panicles of rice plants caused by the fungus Ustilaginoidea virens. A concise total synthesis of ustiloxin D has been achieved via an unprecedented ethynyl aziridine ring-opening of phenol derivatives. The longest linear sequence of the synthesis is 15 steps from commercially available compounds.