[Cl-].[CH3:2][O:3][CH2:4][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C([Li])CCC.O=[CH:30][CH2:31][CH2:32][C:33]([O:35][CH3:36])=[O:34].O>O1CCCC1.CCCCCC>[CH3:2][O:3][CH:4]=[CH:30][CH2:31][CH2:32][C:33]([O:35][CH3:36])=[O:34]34.3 g (0.1 mole) methoxymethyltriphenylphosphonium chloride was suspended in 100 ml dry tetrahydrofuran and cooled to -78° C. under argon. 75 ml (0.1 mole) n-butyllithium solution in hexane was added and the solution allowed to warm to room temperature. After cooling to -78° C. 12.1 g (0.0105 moles) methyl 4-oxobutanoate was added in 50 ml tetrahydrofuran. The solution was allowed to reach room temperature then poured into water and extracted twice with ether. The ether extracts were washed with saturated sodium chloride solution dried and concentrated in vacuo. This was eluted through 250 g silica gel with 1 l ether-hexane 1:1 to give a faintly yellow liquid 9.2 g containing both (Z) and (E) enol ethers.
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