2,2,5,5-Tetramethyltetrahydro-3-ketofuran → 4-[1-(5-Bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyl-dihydrofuran-3-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To an ice-cold solution of 2,2,5,5-tetramethyldihydrofuran-3-one (2.84 g, 20.00 mmol) in anhydrous 1,2-dimethoxyethane (6 ml) is added sodium methoxide (1.19 g, 22.04 mmol) in one portion. After stirring at this temperature for 5 minutes a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (4.84 g, 18.00 mmol) in 1,2-dimethoxyethane (6 ml) is added dropwise over 10 mins, followed by stirring at 0° C. for a further 1 hour. After warming to room temperature the reaction mixture is diluted with ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulphate, filtered and the filtrate evaporated in vacuo to afford 4-[1-(5-bromo-2-trifluoromethoxyphenyl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (7.06 g) as an orange liquid.

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