[CH3:1][O:2][C:3]1[CH:4]=[C:5](Br)[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[O:9][CH3:10].[Li]CCCC.[P:19](Cl)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>C1COCC1>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([P:19]([C:26]2[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=2)[C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[O:9][CH3:10]To a solution of 3,4,5-trimethoxybromobenzene 18 (62.3 g, 0.25 mol) in dry THF (200 ml) was added BuLi solution (169 ml, 1.6M in hexane, 0.27 mol) dropwise at −78° C. within 45 min. The resulting beige-colored suspension was stirred for an additional 1 h at −78° C. Then PPh2Cl (61 g, 0.277 mol. 49.7 ml) was added dropwise. The addition was complete within 2 h. The resulting yellow solution was allowed to warm to 0° C. within 2 h and quenched by addition of NH4Cl solution (200 ml). The organic layer was separated, washed with brine (250 ml), dried (Na2SO4), filtered, and evaporated. The solid was recrystallized from methanol to give 69.5 g (80%) of 19.
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