反应详情

温度

-20 °C

In a nitrogen atmosphere, 0.551 g (1.8 moles) of (S)-2-amino-1,1-diphenyl-4-methylpentan-1-ol hydrochloride was suspended in 5 ml of 1,2-dichloroethane, and after cooling to -20° C., a solution of 0.0681 g (1.8 mmoles) of sodium borohydride in 1 ml of dimethylformamide was added. The temperature of the suspension was raised from -20° C. to room temperature over 2 hours. Thereafter, a solution of 0.348 g (1.2 mmoles) of (E)-1-(4-chlorophenyl)-2-(1,2,4-triazol-1-yl)-4,4-dimethyl-1-penten-3-one in 4 ml of 1,2-dichloroethane was added to this suspension at room temperature, and stirring was carried out for 48 hours. Thereafter, 6 ml of 2N hydrochloric acid was added and stirring was carried out for 2 hours. After removing the intermediate layer by filtration, the organic layer was washed with water and concentrated under reduced pressure, and the residue was purified on a column packed with 2 g of silica gel with chloroform as a developing solvent to obtain 0.35 g of (+)-(E)-1-(4-chlorophenyl)-2-(1,2,4-triazol-1-yl)-4,4-dimethyl-1-penten-3-ol as a crystal. By gas-chromatographic analysis, it was found that the conversion was 96.3%, and the composition of the product was: E-form alcohol, 78.9%; Z-form alcohol, 20.3%; and saturated alcohol, 0.8% (said alcohol means a product obtained by hydrogenation of both the carbonyl group and the double bond contained in the α,β-unsaturated ketone used as a material). By high-performance liquid-chromatographic analysis using an optically active column, it was found that the enantiomer ratio of the produced E-form alcohol was: (+)-isomer, 86.1% and (-)-isomer, 13.9%. The optical yield was 72.2%.

1. temperatureThe temperature of the suspension was raised from -20° C. to room temperature over 2 hours
2. stirringstirring
3. waitwas carried out for 2 hours
4. customAfter removing the intermediate layer
5. filtrationby filtration
6. washthe organic layer was washed with water
7. concentrationconcentrated under reduced pressure
8. customthe residue was purified on a column