反应详情

温度

-20 °C

294 mg of 55% sodium hydride is suspended in 25 ml of dimethoxyethane, and 1.53 g of 3,3-dimethyl-2-oxoheptanephosphonic acid dimethyl ester is instilled. It is stirred for another 30 minutes, cooled to -20° C., and a solution of 1.98 g of VII in instilled in 10 ml of dimethoxyethane and 10 ml of tetrahydrofuran. After 1 hour it is allowed to warm to room temperature, mixed with 0.5 ml of glacial acetic acid, diluted with 200 ml of diethyl ether, shaken three times with 20 ml of salt water each, dried over magnesium sulfate and evaporated in a vacuum to dryness. The residue is chromatographed on silica gel with hexane/5-25% diethyl ether. 1.62 g of VIII is obtained as colorless oil. IR: 2998, 2955, 2863, 1730, 1684, 1621, 1437, 1060, 978/cm.

1. waitAfter 1 hour it is allowed
2. temperatureto warm to room temperature
3. dry with materialdried over magnesium sulfate
4. customevaporated in a vacuum to dryness
5. customThe residue is chromatographed on silica gel with hexane/5-25% diethyl ether