[CH2:1]([Li])[CH2:2][CH2:3]C.[I-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)(C)C.[CH3:29][C:30]([C:33]1[N:38]=[CH:37][C:36]([C:39](=O)[C:40]([O:42][CH2:43][CH3:44])=[O:41])=[CH:35][N:34]=1)([CH3:32])[CH3:31].O>C(OCC)C.CCCCCC>[CH3:29][C:30]([C:33]1[N:38]=[CH:37][C:36]([C:39](=[C:2]([CH3:3])[CH3:1])[C:40]([O:42][CH2:43][CH3:44])=[O:41])=[CH:35][N:34]=1)([CH3:32])[CH3:31]
A 2.5 molar solution of n-butyl lithium in hexanes (5.5 cm3) was added in portions to a suspension of isopropyltriphenylphosphonium iodide (6 g) in dry diethyl ether, whilst the temperature was maintained between -10° and -20° C. After stirring for 1 hour at this temperature, a solution of ethyl 2-[2-(1,1-dimethylethyl)pyrimidin-5-yl]-2-oxo-acetate (3 g) in dry diethyl ether (15 cm3) was added in portions. The stirred reaction mixture was allowed to warm to the ambient temperature, and allowed to stir for 16 hours. The reaction mixture was poured into water and extracted into ethyl acetate. The combined organic extracts were washed, dried over anhydrous magnesium sulphate, and concentrated by removal of the solvent under reduced pressure to give a dark brown oil, which was subjected to chromotography on silica gel, using hexane containing 10% ethyl acetate (by volume), as eluent to give ethyl 2-[2-(1,1-dimethylethyl)pyrimidin-5-yl]-3-methylbut-2-enoate (0.4 g) as a clear oil.
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