Cholesterol and dihydrocholesterol had brought comprehensive attentions and investigations, due to good mesogen units. There is a hydroxy on C(3), and double bonds on C(5)＝C(6) in cholesterol structure, which make the cholesterol molecule have more rigid, so much work all focused on liquid crystalline through synthesizing cholesterol derivatives from the hydroxy on C(3). However the double bond of C(5)＝C(6) is also utilizable functional group, and it can get new series of cholesteric derivatives through introducing proper organic group. So the chemical modification of the double bond on cholesterol is the purpose, it was firstly discussed of the method that 6-bromohexane or acrylic acid link the cholesterol lateral, which was established for the investigation of cholesteric derivatives.

Key words: cholesterol, double bond, chemical modification, cholesteric derivatives