C([O:3][C:4]([C:6]1[CH:11]=[CH:10][C:9]([C:12]2[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=2)=[C:8]([O:19][CH2:20][CH3:21])[CH:7]=1)=O)C.[H-].C([Al+]CC(C)C)C(C)C>C1COCC1>[CH2:20]([O:19][C:8]1[CH:7]=[C:6]([CH2:4][OH:3])[CH:11]=[CH:10][C:9]=1[C:12]1[CH:13]=[CH:14][C:15]([F:18])=[CH:16][CH:17]=1)[CH3:21]To a solution of 2-ethoxy-4′-fluoro-biphenyl-4-carboxylic acid ethyl ester (0.50 g, 1.73 mmol, 1.0 equiv) in anhydrous THF (10 mL) was added dropwise at −10° C. diisobutylaluminum hydride (5.2 mL, 5.20 mmol, 3.0 equiv; 1 M solution in hexane) and the ccolong bath removed. After stirring for an additional time period of 60 min at rt, the reaction mixture was carefully poured on crashed ice/diluted HCl, extracted twice with ethyl acetate, the combined organic phases washed with water and a sat. solution of NaCl, dried over MgSO4 and concentrated by evaporation under reduced pressure. The title compound was isolated in quantitative yield (0.43 g) as a colorless viscous oil, sufficiently pure for the next step. MS (ISP): 229.3 [M+H−H2O]1.
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