Hydrogen Fluoride/Tetrahydrofuran as a Fluorinating Medium. A General Synthesis of 1,1,1,2-Tetrafluoro-2-alkenes

A general and simple two step synthesis of 1,1,1,2-tetrafluoro-2-alkenes is presented. The key step is the rearrangement-conversion of 1,1,2-trifluoro-1-alken-3-ols under the influence of hydrogen fluoride/tetrahydrofuran (5:1) as a fluorinating medium.