text: Tetrafluoroethane is typically made by reacting trichloroethylene with hydrogen fluoride:
  :CHCl=CCl + 4 HF → CFCHF + 3 HCl
  It reacts with butyllithium to give trifluorovinyl lithium:
  :CFCHF + 2 BuLi → CF=CFLi + LiF  +  2 BuH