Definition: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Input: Grignard reagents cannot form without the presence of one of these compounds, and tetrahydrofuran is a cyclic version of one of them. Oxonium compounds are formed when they react with strong inorganic or Lewis acids, and oxidation of them results in an unstable peroxide, and they can be formed dehydration of an alcohol or catalytic hydration of an olefin. Manufactured via Williamson synthesis, specialized ones that that surround specific metal ions are referred to as crown types. FTP, identify this class of organic compounds that features an oxygen atom bonded to two carbon atoms.
Output:
Science