反应详情

In a nitrogen atmosphere, a solution of 0.272 g of (+)-norephedrine in 4 ml of 1,2-dichloroethane was added dropwise at -78° C. to a mixture comprising 1.8 ml of a 0.500M diborane-tetrahydrofuran solution and 2 ml of 1,2-dichloroethane, and the temperature of the resulting mixture was raised from -78° C. to room temperature over about 2 hours. Thereafter, to this solution was added dropwise at room temperature a solution of 0.39 g of (E)-1-(2,4-dichlorophenyl)-2-(1,2,4-triazol-1-yl)-4,4-dimethyl-1-penten-3-one (E/Z=99.9/0.1) in 4 ml of 1,2-dichloroethane, and stirring was carried out for 24 hours. Thereafter, 6 ml of 2M hydrochloric acid was added to the reaction solution, followed by stirring for about 2 hours. The organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified on a column packed with 2 g of silica gel using a chloroform solvent and then concentrated under reduced pressure to obtain 0.39 g of (-)-(E)-1-(2,4-dichlorophenyl)-2-(1,2,4-triazol-1-yl)-4,4-dimethyl-1-penten-3-ol as a crude crystal. The conversion was 98.6%, and the composition of the product obtained was: E-form alcohol, 98.6% and Z-form alcohol, 1.4%.

1. temperaturethe temperature of the resulting mixture was raised from -78° C. to room temperature over about 2 hours
2. stirringby stirring for about 2 hours
3. washThe organic layer was washed with water
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified on a column
7. concentrationconcentrated under reduced pressure