Acetic Acid → Triapenthenol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a nitrogen atmosphere, 0.338 g (1.8 mmoles) of (-)-norephedrine hydrochloride was suspended in a mixture comprising 15.4 μl (0.27 mmole) of acetic acid and 5 ml of 1,2-dichloroethane, and after cooling to -30° C., a solution of 0.0749 g (1.98 mmoles) of sodium borohydride in 1 ml of dimethylformamide was added. The temperature of the resulting suspension was raised from -30° C. to room temperature over 2 hours. Thereafter, to this suspension was added at room temperature a solution of 0.31 g (1.2 mmoles) of (E)-1-cyclohexyl-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-one (E/Z=99.9/0.1) and 10.3 μl (0.18 mmole) of acetic acid in 1,2-dichloroethane, and stirring was carried out for 24 hours. The subsequent treatment was carried out in the same manner as in Example 6 to obtain (-)-(E)-1-cyclohexyl-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol. The conversion was 100%, and the composition of the product obtained was: E-form alcohol, 97.4% and Z-form alcohol, 2.6%. The enantiomer ratio of the E-form alcohol was: (-)-isomer, 77.7% and (+)-isomer, 22.3%.

Herkunft & Nachweise