We have designed a new approach to synthesize brookite, i.e., to extract alkali-metal ions from K0.8Ti1.73Li0.27O4 (KTLO) and to apply simultaneous heat treatment to the remaining lepidocrocite-type layers of TiO6 octahedra. For the alkali-metal ion extraction and the simultaneous heat treatment, KTLO was heated at 400 degrees C with polytetrafluoroethylene (PTFE) in flowing Ar. PTFE has been found to be an effective agent to extract strongly electropositive alkali-metal ions from KTLO because of the strong electronegativity of F as its component. The product of this reaction consists of a mixture of brookite, K2CO3, LiF, and PTFE derivatives, indicating the complete extraction of K+ and Li+ from KTLO and formation of brookite from the lepidocrocite-type layer of TiO6 octahedra as a template. This brookite has a partial replacement of O-2(-) with F- and/or slight oxygen deficiency; thus, its color is light-bluish gray. Fully oxidized brookite formation and complete decomposition of PTFE derivatives have been achieved by further heating in flowing air, and coproduced alkali-metal salts have been removed by washing in water. Powder X-ray diffraction, Raman spectroscopy, and chemical analysis results have confirmed that the final brookite product treated at 600 degrees C is single phase, and it is white. The method to extract alkali-metal ions from a crystalline material using PTFE is drastically different from the common methods such as soft-chemical and electrochemical reactions. It is likely that this new synthetic approach is applicable to other layered systems to prepare a diverse family of compounds, including novel metastable ones.