TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The method comprises: step (a) dehydration of (II) using dehydrating agent in organic solvent at 0-100 degrees C for 0.5-4 hours to obtain (III), where the dehydrating agent is boron trifluoride-diethyl ether complex, boron trifluoride-acetic acid complex, boron trifluoride-tetrahydrofuran complex or boron trifluoride-acetonitrile complex, and the molar ratio of (II) to dehydrating agent is 1:1-10; step (b) reacting (III) with acetylene at 17 position of carbonyl group in ethanol at -20 to 0 degrees C for 1-5 hours under action of potassium hydroxide to obtain (IV); step (c) refluxing (IV), organic base and dehydrating agent in an organic solvent for 1-4 hours to obtain (V), where the molar ratio of (IV) to dehydrating agent is 1:1-5, the molar ratio of (IV) to organic base is 1:5-20, the dehydrating agent is phosphorus oxychloride, phosphorus pentachloride or thionyl chloride, and the organic base is 1,8-diazabicyclo(5.4.0)undec-7-ene,triethylamine, pyridine or 2,6-lutidine; step (d) reacting (V) with formic acid at -20 to 100 degrees C for 1-12 hours to obtain (VI), where the molar ratio of (V) to formic acid is 1:5-50, and the acid is formic acid, acetic acid, perchloric acid, trifluoromethane sulfonic acid or trifluoroacetic acid; step (e) epoxidation of (VI) with tert-butylhydroperoxide and benzyl trimethyl ammonium hydroxide in organic solvent at -10 to 40 degrees C for 1-12 hours to obtain (VII), where the molar ratio of (VI), tert-butylhydroperoxide and benzyl trimethyl ammonium hydroxide is 1:1-10:0.1:5; step (f) reacting (VII) and base in anhydrous methanol at -10 to 50 degrees C for 10-30 minutes, and then adding periodate compound and reacting for 1-10 hours to obtain (VIII), where the molar ratio of (VII) to periodate compound is 1:1-10, the molar ratio of (VII) to base is 1:1-20, the periodate compound is (diacetoxyiodo)benzene or (bis(trifluoroacetoxy)iodo)benzene, and the alkali is univalent metal hydroxide, hydride and/or acetate salts; step (g) reacting (VIII) with acid in organic solvent at 0-40 degrees C for 0.5-4 to obtain (IX), where the acid is p-toluenesulfonic acid, acetic acid, camphor sulfonic acid or sulfuric acid, and the molar ratio of (VIII) to acid is 1:0.1-5; step (h) epoxy ring opening of (IX) under action of 40% hydrobromic acid solution in organic solvent at 10-50 degrees C for 0.5-2 hours to obtain (X), where molar ratio of (IX) to 40% hydrobromic acid is 1:1.5-10; step (i) hydrogenation and debromination of (X) in presence of Raney-nickel in organic solvent at 0-50 degrees C for 0.5-10 hours to obtain (XI), where the weight ratio of (X) to Raney-nickel is 1:10-20; step (j) reacting (XI) with butyrate under action of p-toluenesulfonic acid in organic solvent at 0-40 degrees C for 0.5-2 hours to obtain (XII), where the molar ratio between (XI), butyrate and p-toluenesulfonic acid is 1:1.2-5:0.01-5; step (k) reacting (XII) in organic solvent under action of p-toluenesulfonic acid at 0-50 degrees C for 0.5-10 hours to obtain (XIII), where the molar ratio of (XII) to p-toluenesulfonic acid is 1:0.05-5; step (l) reacting (XIII) with acetic anhydride and pyridine at 0-100 degrees C for 1-10 hours to obtain (XIV), where the molar ratio of (XIV) to acetic anhydride and pyridine is 1:2-100:0.5-5; step (m) epoxidation of (XIV) under presence of 1,3-dibromo-5,5-dimethylhydantoin or N-bromosuccinimide and perchloric acid at -10 to 50 degrees C for 0.5-10 hours to obtain (XV), where the molar ratio between (XIV), 1,3-dibromo-5,5-dimethylhydantoin or N-bromosuccinimide and perchloric acid is 1:1-10:0.2-1; step (n) reacting (XV) with allyl acetate under action of acid at 10-50 degrees C for 0.5-4 hours in organic solvent to obtain (XVI) and finally adding pyridine, where the molar ratio between (XV), allyl acetate, acid and pyridine is 1:2-20:0.5-10:0.1-10 and the acid is concentrated sulfuric acid, p-toluenesulfonic acid or camphor sulfonic acid; step (o) fluorinating (XVI) using fluorinating agent at -40 to 40 degrees C for 1-10 hours in organic solvent to obtain isomeric compounds (XVII) and (XVIII), where molar ratio between (XVII) and (XVIII) is 1:5.6, the molar ratio between (XVI) and fluorinating agent is 1:1.1-5, and the fluorinating agent is selectfluor, accufluor or N-fluorobenzenesulfonimide; and step (p) fluorinating (XVIII) using fluorinating agent -70 to -40 degrees C for 1-10 hours in organic solvent to obtain (I), where the molar ratio between (XVIII) and fluorinating agent is 1:100-500, and the fluorinating agent is aqueous hydrogen fluoride solution, pyridine hydrofluoride or hydrogen fluoride triethylamine solution. Step (a) in which: the dehydrating agent is boron trifluoride-acetic acid complex; the organic solvent is benzene, toluene, dichloromethane or chloroform; the molar ratio between (II) and dehydrating agent is 1:1-5; and reaction is performed in an inert gas nitrogen or argon atmosphere environment. Step (b) in which reaction is performed in an inert gas nitrogen and argon atmosphere environment, and processing obtained product using 10% hydrochloric acid solution. Step (c) in which: the molar ratio between (IV) and dehydrating agent is 1:3; the organic solvent is tetrahydrofuran, dioxane, acetonitrile, benzene, toluene, dimethylsulfoxide, dichloromethane and/or chloroform; and the organic base is 1,8-diazabicyclo (5.4.0) undec-7-ene; and the reaction is quenched using 10% hydrochloric acid. Step (d) in which the organic acid is formic acid. Step (e) in which the organic solvent is methanol, ethanol, acetone, tetrahydrofuran, dioxane, acetonitrile, benzene, toluene, dimethylsulfoxide, dichloromethane and/or chloroform. Step (f) in which: the molar ratio between (VII) and periodate is 1:1-2; the molar ratio between (VII) and base is 1:5-10; the monovalent metal is potassium or sodium; and spin dry solvent, then performing extraction, pumping solvent and finally processing and purifying the product. Step (g) in which the organic solvent is methanol, ethanol, acetone and/or dimethylsulfoxide. Step (h) in which the organic solvent is methanol, ethanol, acetone, tetrahydrofuran, dioxane, acetonitrile, benzene, toluene, thionyl chloride, dichloromethane and/or chloroform. Step (i) in which: the organic solvent is methanol, ethanol, acetone, tetrahydrofuran, dichloromethane and/or chloroform; and filtering the reaction liquid via celite, dried over anhydrous magnesium sulfate, pumping and purifying. Step (j) in which the butyrate is raw material, where R is methyl, ethyl, propyl or butyl. Step (n) in which reaction product is washed with mixed solvent containing acetone and water at volume ratio of 2-10:1-5. Step (n) in which: the acid is p-toluenesulfonic acid; and acid is neutralized by addition of water to the reaction solution and performing purification process. Step (o) in which the organic solvent is acetonitrile, dichloromethane, chloroform, benzene and/or toluene. Step (P) in which: the organic solvent is dichloromethane, chloroform, benzene, toluene and/or tetrahydrofuran; and reaction product is washed with aqueous ammonia.