The Lewis acid boron trifluoride etherate has played an important role in organic synthesis. To accomplish the hydroxylation of double bond, cleavage of epoxides, esterification of acids and many cyclization reaction boron trifluoride etherate proved very useful compared to other Lewis acids. These organic reactions are frequently employed to achieve the synthesis of natural products. In addition, boron trifluoride etherate has also been utilized to realize ketalization, thioketalization, alkylation and many others organic reactions.