[CH:1](NC(C)C)([CH3:3])[CH3:2].C([Li])CCC.[C:13]1([C:19]([CH3:25])=[CH:20][CH2:21][C:22]([OH:24])=[O:23])[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.C(I)(C)C>C1COCC1.CCCCCC.O>[CH:1]([CH:21]([CH:20]=[C:19]([C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)[CH3:25])[C:22]([OH:24])=[O:23])([CH3:3])[CH3:2]
To 3.2 ml (23 mmole) diisopropylamine in 15 ml THF at 0° under nitrogen is added 14.4 ml (23 mmole) 1.6 M n-butyllithium. The reaction is warmed to RT over 2 hr and cooled to 0°, and 2.0 g (11.4 mmole) 4-phenyl-3-pentenoic acid in several ml of THF is added. After 1.5 hr at about 10°, 1.16 ml (11.6 mmole) isopropyl iodide is added and the reaction stirred about 60 hours. The reaction is poured into water and hexane. The aqueous phase is acidified and extracted with ether. The ether extracts are washed to neutrality, dried over calcium sulfate and solvent removed under vacuum to give 2-isopropyl-4-phenyl-3-pentenoic acid.
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