Trifluoromethanesulfonic acid is widely used. It is one of the most powerful organic acids known. It is a versatile synthetic tool. With strong corrosiveness and hygroscopicity, it is widely used in medicine, chemical industry and other industries, such as nucleosides, antibiotics, steroids, proteins, sugars, vitamin synthesis, silicone rubber modification, etc. It can also be used as a catalyst for isomerization and alkylation to prepare 2,3-dihydro-2-indanone and 1-tetrahydronaphthalene ketone and remove glycosides from glycoproteins.