C([Li])CCC.[Br-].[CH3:7][O:8][C:9]1[CH:10]=[C:11]([CH:32]=[C:33]([O:35][CH3:36])[CH:34]=1)[CH2:12][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[CH2:37]([CH2:44][C:45](=O)[CH3:46])[C:38]1[CH:43]=[CH:42][CH:41]=[CH:40][CH:39]=1.C(O)(=O)C>O1CCCC1>[CH3:36][O:35][C:33]1[CH:32]=[C:11]([CH:12]=[C:45]([CH3:46])[CH2:44][CH2:37][C:38]2[CH:43]=[CH:42][CH:41]=[CH:40][CH:39]=2)[CH:10]=[C:9]([O:8][CH3:7])[CH:34]=1A solution of n-butyl lithium (29 ml. of 2.2 M) is added dropwise to 3,5-dimethoxybenzyl triphenylphosphonium bromide (31.5 g.) in tetrahydrofuran (200 ml.) with stirring and the resulting deep red solution is stirred for one-half hour. Benzyl acetone (9.4 g.) is added dropwise and the reaction mixture stirred for 12 hours. It is then adjusted to pH 7 by addition of acetic acid and concentrated under reduced pressure. The residue is extracted with methylene chloride and the extract evaporated to give crude 1-(3,5-dimethoxyphenyl)-2-methyl-4-phenyl-1-butene as an oil. It is purified by chromatography on silica gel (400 g.) and elution with benzene. Yield: 10 g. as an oil.
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