In this dissertation, the application of ionic liquids in three types of organic reaction was studied. The reactions includes dimerization of the a-methylstyrene (AMS), deprotection of acetals(ketals) and asymmetric epoxidation catalyzed by chiral ketones.1. Dimerization of a-methylstyrene (AMS) catalyzed by acidic ionic liquid [Hmim]+ BF_4~ -.( 1 ) 2,4-Diphenyl-4-methyl-l-pentene (1-PT) was produced selectively by dimerization of AMS with catalytic amount of ionic liquid [Hmim]~+ BF_4~ -. With respect to t...