Reaction SMILES: [F:1][C:2]1[C:3]([O:17][CH3:18])=[C:4]([C:8]2([CH2:11][C:12](=[O:16])[C:13]([OH:15])=[O:14])[CH2:10][CH2:9]2)[CH:5]=[CH:6][CH:7]=1.S(=O)(=O)(O)O.[CH2:24](O)[CH3:25]>>[CH2:24]([O:14][C:13](=[O:15])[C:12](=[O:16])[CH2:11][C:8]1([C:4]2[CH:5]=[CH:6][CH:7]=[C:2]([F:1])[C:3]=2[O:17][CH3:18])[CH2:10][CH2:9]1)[CH3:25]
Reactant: COc1c(F)cccc1C1(CC(=O)C(=O)O)CC1
Reactant: CCO
Agent: O=S(=O)(O)O
Product: CCOC(=O)C(=O)CC1(c2cccc(F)c2OC)CC1

Procedure:
The organic phase is separated, and the aqueous phase is extracted several times with diethyl ether. It is washed with brine, dried with sodium sulfate and concentrated by evaporation in a vacuum. After chromatographic purification on silica gel (hexane/ethyl acetate 5%-10%), 28.5 g of 1-(3-fluoro-2-methyoxyphenyl)-cyclohexylnitrile is obtained. 27.5 g (118 mmol) of nitrile is slowly mixed in 430 ml of toluene at −78° C. with 147 ml (176 mmol) of diisobutyl aluminum hydride solution (20% in toluene), and after 3 hours at −78° C., 35 ml of isopropanol was added in drops. It is allowed to heat to −5° C., and 600 ml of a 10% aqueous tartaric acid solution is added. After dilution with ether, it is vigorously stirred, the organic phase is separated, and the aqueous phase is extracted several times with ethyl acetate. It is washed with brine, dried with sodium sulfate and concentrated by evaporation in a vacuum. 27.5 g of aldehyde is obtained as a yellow oil. A solution of 5.7 g (21.2 mmol) of 2-diethylphosphono-2-ethoxyacetic acid ethyl ester in 25 ml of tetrahydrofuran is mixed with 13.6 ml (27.2 mmol) of a 2 M solution of lithium diisopropylamide in tetrahydrofuran-heptane-toluene within 15 minutes while being cooled with ice, and it is stirred for 20 minutes at 0° C. Within 30 minutes, a solution of 5 g (21.2 mmol) of 1-(3-fluoro-2-methoxyphenyl)-cyclohexylformanal in 5 ml of tetrahydrofuran is added in drops at 0° C. After 16 hours at room temperature, ice water is added, and it is extracted several times with ether. It is washed with saturated ammonium chloride solution, dried on sodium sulfate and concentrated by evaporation. The crude product is saponified with 6 g of sodium hydroxide in 100 ml of ethanol and 50 ml of water over 4 days at room temperature. 1.7 g of acid, which is stirred with 35 ml of 2N sulfuric acid and 7 ml of acetic acid at 90° C. over 30 hours, is obtained. After cooling, it is made basic with potassium carbonate, washed with ether and acidified with hydrochloric acid. After extraction with ethyl acetate, washing with saturated sodium chloride solution and removal of the solvent, 1.09 g of the crude keto acid is obtained. 1.09 g (3.7 mmol) of 3-{1-(3-fluoro-2-methoxyphenyl)-cyclopropyl]-2-oxopropionic acid and 0.45 ml of sulfuric acid (96%) are refluxed in 40 ml of ethanol for 2 hours. The batch is concentrated by evaporation in a vacuum, the residue is added in ice water, and it is made basic with saturated sodium bicarbonate solution. It is extracted several times with ethyl acetate, washed with saturated sodium chloride solution, dried (sodium sulfate) and concentrated by evaporation in a vacuum. After chromatographic purification on silica gel (hexane/ethyl acetate 20%), 1.05 g of ethyl-3-[1-(3-fluoro-2-methoxyphenyl)-cyclopropyl]-2-oxopropionate is obtained.