反应详情

Lithium aluminum hydride (1.47 g) was suspended in THF (200 ml). 4-(4′-Hexyloxy-2,3,-difluorophenyl)-cyclohexanone (s-14) (20.0 g) dissolved in THF (50 ml) was added dropwise to the suspension in the temperature range of −20° C. to −10° C., and the stirring was continued in this temperature range for another 2 hours. After the completion of the reaction had been confirmed by means of GC analysis, ethyl acetate and then a saturated aqueous solution of ammonia were added to the reaction mixture under ice-cooling and deposits were removed by filtration through Celite. The filtrate was extracted with ethyl acetate. The combined organic phase was washed successively with water and brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was purified by recrystallization from heptane to give trans-4-(4′-hexyloxy-2,3,-difluorophenyl)-cyclohexanol (s-29) (16.3 g). The yield based on the compound (s-27) was 81.0%.

1. additionwas added dropwise to the suspension in the temperature range of −20° C. to −10° C.
2. temperaturecooling
3. customdeposits were removed by filtration through Celite
4. extractionThe filtrate was extracted with ethyl acetate
5. washThe combined organic phase was washed successively with water and brine
6. dry with materialdried over anhydrous magnesium sulfate
7. distillationThe solvent was distilled off under reduced pressure
8. customthe residue was purified by recrystallization from heptane