[O:1]([CH:9]1[CH2:13][C:12](=[O:14])[CH:11]=[CH:10]1)[Si:2]([C:5]([CH3:8])([CH3:7])[CH3:6])([CH3:4])[CH3:3].[Mg+2].[Br-].[Br-].[H-].[Al+3].[Li+].[H-].[H-].[H-].COC(C)(C)C>C1(C)C=CC=CC=1>[Si:2]([O:1][C@@H:9]1[CH2:13][C@H:12]([OH:14])[CH:11]=[CH:10]1)([C:5]([CH3:8])([CH3:7])[CH3:6])([CH3:4])[CH3:3]A stirred solution of 4-tert-butyldimethylsiloxy-2-cyclopentenone (2.0 g, 9.42 mmol) in anhydrous toluene (15 mL) under an atmosphere of argon is treated with MgBr2 (3.5 g, 19.0 mol). The mixture is cooled to -25° C. and treated with lithium aluminum hydride (178 mg, 4.69 mmol) in one portion, followed by addition of anhydrous tert-butyl methyl ether (3.0 mL). The reaction is stirred at -20° C. for 2 hours and then overnight at room temperature. Additional lithium aluminum hydride (178 mg, 4.69 mmol) is added at room temperature and the reaction is stirred for 2 hours. The reaction is then quenched by slow addition of 1N NaOH (5 mL) followed by filtration through diatomaceous earth. The filtrate is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum to provide the title compound (1.3 g); cis/trans/1-2 +1-4 addition, 90/3/7.
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