Bromomethyl 4-methoxyphenyl ketone → 2-(5-Benzyloxy-2-vinylphenoxy)-1-(4-methoxyphenyl)ethanone

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Reaction Conditions

Reaction Steps

A suspension of methyl triphenyl phosphonium bromide (MTPPB, 16.90 g, 47.31 mmol) in anhydrous THF (50 mL) was cooled in an ice bath and added with potassium tert-butoxide (t-BuOK, 5.31 g, 47.32 mmol) in portions under nitrogen. After stirring at 0° C. for 15 min, a mixture of 4-benzyloxy-2-hydroxybenzaldehyde (1)(9.0 g, 39.43 mmol), t-BuOK (4.87 g, 43.40 mmol) and THF (50 mL) was added, and the resultant mixture was stirred at 0° C. for 2 hrs. Thereafter, the mixture was heated under reflux, and a solution of 2-bromo-4′-methoxyacetophenone (10.85 g, 47.36 mmol) in THF (30 mL) was added dropwise. After stirring under reflux for 1 hr (TLC monitoring), the mixture was quenched with a saturated NH4Cl solution. After removal of most of the THF in vacuo, the resultant residue was extracted six times with EtOAc (50 mL). The organic layers were combined, washed with a saturated NaCl solution, and dried with anhydrous MgSO4. After filtration, the filtrate was concentrated in vacua, followed by purification via silica gel column chromatography (ethyl acetate/n-hexane=1:15), thus giving the title compound 2a as a colorless crystal (11.81 g, 80% yield).

Provenance & Evidence