反应详情

To a solution of 4-(4′-chloro-4-ethylbiphenyl-3-yl)-2,2,6,6-tetramethylpyran-3,5-dione (0.077 g, 0.20 mmol) dissolved in anhydrous dichloromethane (3 ml) is added triethylamine (0.031 ml, 0.22 mmol) then pivaloyl chloride (0.027 ml, 0.22 mmol). This mixture is stirred at room temperature for 3 hours, then diluted with dichloromethane (15 ml) and washed with distilled water (2×10 ml). Organic fractions are combined, dried over magnesium sulphate, then concentrated to give a crude oil which is purified by flash chromatography (100% hexane to hexane/ethyl acetate 9:1 ratio) to afford 2,2-dimethylpropionic acid 4-(4′-chloro-4-ethylbiphenyl-3-yl)-2,2,6,6-tetramethyl-5-oxo-5,6-dihydro-2H-pyran-3-yl ester (0.090 g) as a colourless gum.

1. washwashed with distilled water (2×10 ml)
2. dry with materialdried over magnesium sulphate
3. concentrationconcentrated
4. customto give a crude oil which
5. customis purified by flash chromatography (100% hexane to hexane/ethyl acetate 9:1 ratio)