Tetrahydrofuran → Methyl 4-ethenylbenzoate

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Reaction Steps

To a three-neck, round-bottom flask equipped with an overhead stirrer, addition funnel, and a nitrogen inlet was added sodium hydride as a 60 percent dispersion (58.5 g, 1.46 mole). The sodium hydride was washed with THF (300 mL) then fresh THF (2000 mL) added. To the well-stirred suspension at room temperature was added methyltriphenyl-phosphonium bromide (500.1 g, 1.40 mole) over 35 minutes. After another 40 minutes of stirring, a solution of methyl p-formylbenzoate (218.9 g, 1.33 mole) in THF (600 mL) was added over 20-25 minutes. The mixture was then stirred at room temperature overnight for a total of 18 hours. The mixture was then filtered and the filtrate concentrated in vacuo. The residue was then treated with a 50 percent solution of ethyl acetate in hexanes (1400 mL) and filtered again. This filtrate was then concentrated in vacuo and placed on a large chromatography column (1400 mL of silica gel 60, 35-70 mesh packed with a 5 percent solution of ethyl acetate in hexanes) and eluted with a 5 percent solution of ethyl acetate in hexanes. The desired fractions were combined and concentrated in vacuo to provide 180.67 g (83.5 percent) of oil which slowly solidified to a white waxy solid. Proton NMR (Gemini 300 MHz in deuterochloroform): delta 7.98 (2H), 7.42 (2H), 6.72 (1H), 5.82 (1H), 5.37 (1H), 3.88 (3H). FDMS confirmed a mass of 162.

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