[CH3:1][C:2]([CH3:5])([O-])[CH3:3].[K+].[Si:7]([O:14][C:15]1[CH:20]=[C:19]([O:21][Si:22]([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23])[CH:18]=[CH:17][C:16]=1C1CCC(=O)CC1)([C:10]([CH3:13])([CH3:12])[CH3:11])([CH3:9])[CH3:8].O1C[CH2:39][CH2:38][CH2:37]1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[C:10]([Si:7]([O:14][C:15]1[CH:20]=[C:19]([O:21][Si:22]([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23])[CH:18]=[CH:17][C:16]=1[CH:38]1[CH2:39][CH2:3][C:2](=[CH2:5])[CH2:1][CH2:37]1)([CH3:8])[CH3:9])([CH3:13])([CH3:12])[CH3:11]To a round bottomed flask was added methyltriphenylphosphonium bromide (0.99 g) and tetrahydrofuran (30 ml). The resulting suspension was cooled to 0° C. and potassium tert-butoxide (0.31 g) was added in one portion. The resulting solution was stirred at 0° C. for 0.5 hr, then 4-(2,4-bis{[tert-butyl(dimethyl)silyl]oxy}phenyl)cyclohexanone (0.60 g) added as a solution in tetrahydrofuran (10 ml). The solution was stirred for 1 hr at 0° C., then allowed to warm to room temperature and stirred for 15 hr. The reaction mixture was partitioned between ethyl acetate (20 ml) and saturated ammonium chloride solution (20 ml). The layers were separated and the aqueous layer extracted with ethyl acetate (2×20ml). The combined organic phases were washed with brine (20 ml), dried over magnesium sulfate, filtered and concentrated in vacuo. Purification via flash chromatography (SiO2, ethyl acetate/petroleum ether, 1:9 v/v) furnished the title compound (0.56 g, 93%) as a colourless oil. δH (CDCl3): 0.17 (6H, s), 0.24 (6H, s), 0.97 (9H, s), 1.03 (9H, s), 1.34-1.47 (2H, m), 1.86-1.94 (2H, m), 2.10-2.20 (2H, m), 2.35-2.43 (2H, m), 3.00 (1H, tt), 4.64 (2H, m), 6.29 (1H, d), 6.39 (1H, dd), 6.94 (1H, d).
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