[Li]CCCC.[CH3:6][O:7][C:8]1[CH:20]=[CH:19][C:18]2[C:17]3[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=3)[CH2:11][C:10]=2[CH:9]=1.Br[CH2:22][CH2:23][CH:24]1[O:28][CH2:27][CH2:26][O:25]1.CCOC(C)=O>C1COCC1.CCCCCC>[CH3:6][O:7][C:8]1[CH:20]=[CH:19][C:18]2[C:17]3[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=3)[CH:11]([CH2:22][CH2:23][CH:24]3[O:28][CH2:27][CH2:26][O:25]3)[C:10]=2[CH:9]=1A solution of n-BuLi (2.5 M in hexane, 6.4 mL, 16.0 mmol) was slowly added into a cooled (-78° C.) solution of 2-methoxyfluorene (prepared according to example 10; 3.1 g, 15.8 mmol) in 100 ml THF. The reaction mixture became dark red and a solid started to precipitate out. After 30 minutes 2-(2-bromoethyl)-1,3-dioxolane (5.8 g, 32.0 mmol) was added to the cold solution and the solution was warmed up to room temperature. The reaction mixture was stirred overnight at room temperature. TLC (silica, 25% EtOAc in hexane) was used to monitor the reaction. The reaction was quenched with water and the product was extracted into EtOAc. The organic layer was washed with water (×3), dried over magnesium sulfate and evaporated. Short path chromatography (5% ethyl acetate/hexane) afforded 3.2 g (62.5%) of the product.
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