[CH2:1]([Li])[CH2:2][CH2:3][CH3:4].C#C.I[CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18]I.[CH3:20][CH2:21][CH2:22][CH2:23][CH2:24]C>O1CCCC1>[CH3:4][C@:3]12[CH2:24][CH2:23][C@H:22]3[C@@H:11]([CH2:12][CH2:13][CH:14]4[C@:21]3([CH3:20])[CH2:18][CH2:17][CH2:16][CH2:15]4)[C@@H:10]1[CH2:9][CH:1]=[CH:2]2To a solution of butyllithium (2.84 ml of a 1.6M solution in hexane, 4.5 mmol) in dry tetrahydrofuran (THF, 45 ml) was added dropwise a solution of acetylene 9 (500 mg, 1.13 mmol) in dry THF (10 ml) at -40° C. The reaction mixture was then allowed to warm up to -10° C. and stirred for 1 h. At this temperature, a solution of 1,10-diiododecan (2.15 g, 5.4 mmol) in dry THF (5 ml) was added in one portion. The cooling bath was removed and the reaction mixture was stirred at room temperature for 15 h. Then, the solution was diluted with 100 ml of ether and was washed with water (6×30 ml), dried, filtered and concentrated to an oil. The residue was purified by flash chromatography (hexane:acetone, 96:4), followed by preparative thin-layer chromatography (TLC) to give 208 mg, 26% of compound 10 (n=10)
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