NOVELTY - Preparation of ezetimibe comprises mixing 4-O-protected-hydroxy benzene ethyl ketone compound (I) with carbonic acid diester in the presence of base, condensing with 4-aniline, processing asymmetric reduction, alkylating, processing asymmetric reduction, reacting with methanesulfonyl chloride to obtain (4-O-protected-hydroxyphenyl) pentyl methanesulfonate (IX), reacting in the presence of phase transfer catalyst, processing cyclization to generate 2-azetidinone compound (X), removing protecting group to crude product, and recrystallizing to obtain ezetimibe.    USE - Method for preparing ezetimibe (claimed).    ADVANTAGE - The method is stable, has mild reaction condition, reduces three wastes, and is suitable for industrial production.    DETAILED DESCRIPTION - Preparation of ezetimibe comprises mixing 4-O-protected-hydroxy benzene ethyl ketone compound of formula (I) with carbonic acid diester in the presence of base to generate 4-O-protected-hydroxy benzene formyl ester compound of formula (II), condensing with 4-aniline, processing asymmetric reduction with 3-(4-fluorophenyl)-3-carbonyl epichlorohydrin to obtain chloropropane compound of formula (V), alkylating N-(4-fluorophenyl)-4-O-protected-hydroxy benzoyl acetamide compound of formula (III) and O-protected-hydroxy epichlorohydrin compound of formula (VI) to obtain O-protected-hydroxyl benzoyl pentanamide compound of formula (VII), processing asymmetric reduction, reacting with methanesulfonyl chloride to obtain (4-O-protected-hydroxyphenyl) pentyl methanesulfonate compound of formula (IX), reacting in the presence of phase transfer catalyst, processing cyclization to generate 2-azetidinone compound of formula (X), removing protecting group to crude product, and recrystallizing to obtain ezetimibe.    R1=benzyl, methyl, or TBS, carbonic diester;    R2=methyl or ethyl; and    R3=t-butyl dimethyl silicon, triethyl silicon, or benzyl.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the preparation of ezetimibe (Drawing includes non-English language text).