Acetone Cyanohydrin → 2,2,6,6-Tetramethyl-4-(4-chloro-2-nitrobenzoyl)-2H-pyran

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Reaction Steps

To a mixture of 2,2,6,6.tetramethyl.5.(4.chloro.2.nitrobenzoyloxy)-3,6-dihydro-2H-pyran-3-one (5.97 g, 16.9 mmol) and triethylamine (4,70 ml, 33.8 mmol) in 30 ml of acetonitrile is added acetone cyanohydrin (0.5 ml), and the mixture is stirred at RT for 24 hours. The reaction mixture is diluted with ether and extracted with aqueous 5% K2CO3. The aqueous layer is made acidic with conc. HCl and extracted with ether. The combined organic layers are dried and evaporated to give light yellow crystals, which are purified to yield 2,2,6,6.tetramethyl-4-(4-chloro-2-nitrobenzoyl) -2H-pyran-3,5-(4H,6H)-dione (compound 8, Table A).

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