反应详情

Under nitrogen atmosphere, to a solution of 2-(6-bromo-2,2-dimethylhexyloxy)-tetrahydropyran (17.6 g, 60 mmol) and diethyl malonate (4.8 g, 30 mmol) in anhydrous dimethyl sulfoxide (145 mL) was added sodium hydride (60% dispersion in mineral oil, 2.9 g, 72 mmol) under cooling with a water bath. Tetra-n-butylammonium iodide (2.1 g, 3.6 mmol) was added and the mixture was stirred for 16 h at room temperature. The reaction mixture was carefully hydrolyzed with water (140 mL) under cooling with a water bath. The mixture was extracted with diethyl ether (3′60 mL). The combined organic layers were washed with water (4×50 mL) and brine (50 mL), dried over sodium sulfate, and concentrated in vacuo, affording 2,2-bis[5,5-dimethyl-6-(tetrahydropyran-2-yloxy)-hexyl]malonic acid diethyl ester (17.3 g, 82%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.41 (t, 2H, J=3.1 Hz), 4.01 (q, 4H, J=7.0 Hz), 3.82-3.70 (m, 2H), 3.50-3.30 (m, 4H), 2.87 (d, 2H, J=9.1 Hz), 1.80-1.35 (m, 16H), 1.30-0.95 (m, 18H), 0.88-0.74 (m, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (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 a water bath
3. extractionThe mixture 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 materialdried over sodium sulfate
6. concentrationconcentrated in vacuo