2-Hydroxyphenyltriphenylphosphonium bromide → Methyl E-4-{7-cyano-3-[2-(2-hydroxyphenyl)vinyl]heptyl}benzoate

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Reaction Steps

9.07 ml (14.52 mmol) of a 1.6 M solution of n-butyllithium in hexane are slowly added dropwise to a suspension of 3.26 g (7.26 mmol) of 2-hydroxyphenyltriphenylphosphonium bromide in 40 ml of dry THF at 0° C., and the mixture is stirred for 5 minutes. Then, at this temperature, 1.49 g (5.19 mmol) of methyl 4-(7-cyano-3-formylheptyl)benzoate from Example 94A in 10 ml of dry THF are slowly added dropwise. The reaction mixture is stirred at 0° C. for 10 minutes. The cooling is then removed, and the reaction solution is stirred at room temperature for 10 minutes and then mixed with silica gel and concentrated to dryness. The resulting residue is purified directly by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 1:2→1:5). 1.71 g (75% purity, 3.40 mmol, 65% yield) of an oil are obtained.

Provenance & Evidence