21,21,21‐Trifluorothevinone: the Straightest Way to Fluorinated Thevinols and Orvinols

Thevinone is the key starting material for preparations of thevinols and orvinols, the well‐known opioid receptor ligands. Some of them have found applications both in human medicine and veterinary. Herein we disclose the convenient multigram‐scale preparation of 21,21,21‐trifluorothevinone that opens the straightest way to the relative C(21)‐fluorinated thevinols and orvinols, the putative opiod receptor ligands as well as the valuable objects for investigations of the structure‐activity relationship in the thevinol/orvinol series. 21,21,21‐Trifluorothevinone was prepared by a reaction of the thebaine‐based [4+2]‐adduct of acroleine with CF3SiMe3 followed by the Swern oxidation of the fluorinated alcohol thus obtained. Fluorinated opioid ligands: The multigram‐scale synthesis of 21,21,21‐trifluorothevinone is reported. This precursor may enable to prepare a variety of fluorinated analogues of thevinone‐based opioid receptor ligands. The examples are given.