Synthesis of trifluoromethyl-substituted cyclic compounds

Abstract

Study of trifluoromethyl-substituted 5- and 6-membered cyclic compounds is worthwhile owing to the widespread presence of such rings in natural products. Moreover this fluorinated group can induce modified physical and biological properties. Synthesis of cyclopentanones and cyclohexanones bearing a trifluoromethyl substituent at their α, β or γ positions has been achieved in various ways: perfluoroalkylation or annelation of carbonyl derivatives, Michael or Diels-Alder condensation, etc. At a bicyclic junction, the angular trifluoromethyl group has been introduced following Torgov or Kametani strategies. New steroids trifluorinated at the 18 or 19 position have been obtained in this manner.