C[Si](Cl)(C)C.[CH:6]1([Mg]Cl)[CH2:11][CH2:10][CH2:9][CH2:8][CH2:7]1.[CH3:14][C:15]([CH3:22])=[CH:16][C:17]([O:19][CH2:20][CH3:21])=[O:18].[Cl-].[NH4+]>O1CCCC1.[Cu]Cl>[CH:6]1([C:15]([CH3:22])([CH3:14])[CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:11][CH2:10][CH2:9][CH2:8][CH2:7]1Trimethylsilyl chloride (1.3 ml, 10.2 mmol), copper (I) chloride (30 mg, 0.3 mmol) and cyclohexylmagnesium chloride (4.6 ml, 2N in diethyl ether, 9.2 mmol) were added slowly to an ice-cooled solution of ethyl 3,3-dimethylacrylate (1 g, 8.5 mmol) in tetrahydrofuran (10 ml). The solution was stirred for 10 minutes, then allowed to warm to room temperature and stirred for an hour. Saturated aqueous ammonium chloride solution (10 ml) was added and the mixture was partitioned between water (10 ml) and diethyl ether (20 ml). The layers were separated and the aqueous phase was extracted with diethyl ether (2×10 ml). The combined organic extracts were dried (MgSO4) and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel using ethyl acetate:pentane(5:95) as eluant to afford the title compound, 1.2 g. 1H-NMR (CDCl3, 400 MHz) δ: 0.75 (m, 8H), 1.05-1.28 (m, 7H), 1.62 (m, 1H), 1.78 (m, 4H), 2.20 (s, 2H), 4.10 (q, 2H).
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