反应详情

Under nitrogen atmosphere, to a solution of 2-(6-bromo-2,2-dimethyl-hexyloxy)-tetrahydropyran (17.6 g, 60 mmol) and diethyl malonate (4.8 g, 30 mmol) in anhydrous DMSO (145 mL) was added sodium hydride (60% dispersion in mineral oil, 2.88 g, 72 mmol) under cooling with a water-bath. Tetra-n-butylammonium iodide (2.1 g, 3.6 mmol) was then added. The mixture was stirred for 16 h at room temperature. Water (140 mL) was added carefully to the reaction mixture under cooling with water-bath. The product was extracted with diethyl ether (3 60 mL) and the combined organic layers were washed with water (4 50 mL) and brine (50 mL). The solution was dried over sodium sulfate and concentrated in vacuo to give 2,2-bis-[5,5-dimethyl-6-(tetrahydropyran-2-yloxy)-hexyl]-malonic acid diethyl ester (17.3 g, 82.3%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm) 4.41 (t, J=3.1 Hz, 2H), 4.01 (q, J=7.0 Hz, 4 H), 3.82-3.70 (m, 2H), 3.50-3.30 (m, 4H), 2.87 (d, J=9.1 Hz, 2H), 1.80-1.35 (m, 16H), 1.30-0.95 (m, 18H), 0.88-0.74 (m, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm) 172.0, 99.1, 76.6, 61.9, 60.9, 57.6, 39.2, 34.3, 32.3, 30.7, 25.7, 25.0, 24.6, 24.6, 24.3, 19.5, 14.2.

1. temperatureunder cooling with a water-bath
2. temperatureunder cooling with water-bath
3. extractionThe product was extracted with diethyl ether (3 60 mL)
4. washthe combined organic layers were washed with water (4 50 mL) and brine (50 mL)
5. dry with materialThe solution was dried over sodium sulfate
6. concentrationconcentrated in vacuo