Hydrochloric Acid → Triapenthenol

Participants

Reaction Conditions

Reaction Steps

In a nitrogen atmosphere, 0.275 g (0.90 mmole) 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 0.034 g (0.90 mmole) of sodium borohydride in 0.5 ml of dimethylformamide was added. The temperature of the suspension was then raised from -20° C. to room temperature over 2 hours. Thereafter, a solution of 157 mg (0.60 mmole) of (E)-1-cyclohexyl-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-one in 2 ml of 1,2-dichloroethane was added dropwise to this suspension at room temperature, and stirring was carried out for 24 hours. To this reaction solution was added 6 ml of 2N hydrochloric acid, and after removing liberated (S)-2-amino-1,1-diphenyl-4-methylpentan-1-ol hydrochloride by filtration, the organic layer was washed with water and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel to obtain 0.158 g of (-)-(E)-cyclohexyl-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol. The conversion was 93.7%, and the composition of the product was: E-form alcohol, 95.7% and Z-form alcohol, 4.3%. The enantiomer ratio of the E-form alcohol was: (+)-isomer, 18.8% and (-)-isomer, 81.2%.

Provenance & Evidence