TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The Lewis acid is cerium trichloride, titanium tetrachloride, cobalt chloride, nickel chloride or zinc chloride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The acylation reaction is carried out by mixing (1S,2S)-2-amino-3-fluoro-l-(4-(methylsulfonyl)phenyl)-1-propanol with acylating agent and alkali (B1), and reacting in presence of solvent (s1). The cyclization reaction is carried out by mixing (1S,2S)-2-amino-3-fluoro-l-(4-(methylsulfonyl) phenyl)-1-propanol reaction product, sulfonic acid esterification agent and alkali (B2) in a molar ratio of 1:1-3:1.2-5 in presence of solvent (s2). 2-Bromo-3-chloro-l-(4-(methylthio)phenyl)-1-propanone and hydrogen peroxide in a molar ratio of 1:2-10 are reacted at 20-60 degrees C for 6-24 hours in presence of solvent (s3) and catalyst. 2-Bromo-3-chloro-l-(4-(methylsulfonyl) phenyl)-1-propanone, chiral amine (a) and alkali (B3) are mixed in a molar ratio of 1:1-1.5:2-3 and reacted in presence of solvent (s4) for 2-6 hours. The method further involves adding aluminum trichloride and 3-chloropropionyl chloride to dichloromethane and dripping thioanisole to obtain 3-chloro-1-(4-(methylthio)phenyl)-1-propanone. Preferred Composition: The molar ratio of (1S,2S)-2-amino-3-fluoro-l-(4-(methylsulfonyl)phenyl)-1-propanol with acylating agent, acylating agent and alkali is 1:1-3:1.2-4. The solvent (s1) is chosen from methanol, tetrahydrofuran, dichloromethane, chloroform and 1,2-dichloroethane. The alkali (B1) is chosen from potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, diisopropylethylamine and pyridine. The acylating agent is chosen from benzoyl chloride, methyl benzoate, ethyl benzoate, di-tert-butyl-dicarbonate, methyl dichloroacetate and ethyl dichloroacetate. The solvent (s2) is chosen from dichloromethane, chloroform, 1,2-dichloroethane and tetrahydrofuran. The alkali (B2) is chosen from potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, diisopropylethylamine, and pyridine. The solvent (s3) is chosen from methanol, ethanol, isopropanol and acetonitrile. The catalyst is chosen from potassium dichromate, chromium trioxide, manganese dioxide, ferric chloride, sodium tungstate dihydrate, molybdenum oxide, aluminum oxide, iron oxide, acetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid and boric acid. The solvent (s4) is chosen from dichloromethane, chloroform, 1,2-dichloroethane, methanol and ethanol. The alkali (B3) is chosen from potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, diisopropylethylamine, and pyridine. The solvent used for recrystallization is chosen from dichloromethane, chloroform, 1,2-dichloroethane, toluene, xylene, methanol, ethanol, isopropanol, acetonitrile, acetone and ethyl acetate. The molar ratio of 1-R1-2-(R)-(4-(methylsulfonyl)phenyl)carbamoyl aziridine, reducing agent, and Lewis acid is 1:0.5-2:0.5-1.5. The reducing agent is sodium borohydride, potassium borohydride, diborane, lithium-aluminum trimethoxyhydride, or lithium-aluminum tributoxyhydride. The molar ratio of compound (B) and triethylamine salt of hydrofluoric acid is 1:1.2-10. The solvent (s5) is chosen from dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, dioxane, chlorobenzene, toluene, xylene, diethyl ether, methyl t-butyl ether, diisopropyl ether, N-methylpyrrolidone, dimethylformamide, and dimethyl sulfoxide. The mass ratio of compound (2) to solvent (s5) is 3-15:1. The mass ratio of (1S,2S)-3- fluoro-1-(4-(methylsulfonyl)phenyl)-2-(R1-amino)-1-propanol and palladium-carbon catalyst is 1:0.02-0.1. The molar ratio of 3-chloropropionyl chloride, aluminum trichloride and thioanisole is 1:1-1.6:1-1.5. The molar ratio of 3-chloro-1-(4-(methylthio)phenyl)-1-propanone and bromine is 1:1-1.3.