2,2,5,5-Tetramethyltetrahydro-3-ketofuran → HCID 66823579, compound

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Reaction Steps

To an ice-cold solution of dihydro-2,2,5,5-tetramethylfuran-3-one (15.70 g, 0.11 mol) in anhydrous 1,2-dimethoxyethane (285 ml) is added sodium methoxide (6.50 g, 0.12 mol) in one portion, and the mixture is stirred at this temperature for 30 minutes. A solution of 2′,4′-dichloro-4-cyclopropylbiphenyl-3-carbaldehyde (13.70 g, 0.047 mmol) is then added dropwise over 20 minutes, maintaining temperature below 10° C. The reaction mixture is stirred at this temperature for 2 hours, then allowed to warm to room temperature before diluting with diethyl ether and distilled water. The two phases are separated, and the aqueous phase is extracted again with diethyl ether (×2). Organic fractions are combined, washed with brine, then dried over magnesium sulphate. The suspension is filtered and filtrate concentrated in vacuo. The aqueous phase is further acidified with 2M hydrochloric acid then extracted again with diethyl ether (×2), dried over magnesium sulfate and concentrated in vacuo. All organics are combined, then diluted with toluene and azeotroped (×4) to afford 4-[1-(2′,4′-dichloro-4-cyclopropylbiphenyl-3-yl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (20.0 g) which is of sufficient purity to use directly in the next step.

Provenance & Evidence