Acetic Acid → Uniconazole

Beteiligte Stoffe

Reaktionsschritte

In a nitrogen atmosphere, 0.393 g (0.0065 mole) of acetic acid was added to a suspension of 8.18 g (0.0436 mole) of (-)-norephedrine hydrochloride in 62.17 g of chlorobenzene, and then a solution of 1.815 g (0.0480 mole) of sodium borohydride in 9.35 g of dimethylformamide was added dropwise to this suspension at 5° to 10° C. for 1.5 hours. Thereafter, the resulting mixture was stirred at room temperature for 1 hour, and then a solution of 8.42 g (0.0291 mole; E/Z=99.8/0.2) of (E)-1-(4-chlorophenyl)-2-(1,2,4-triazol-1-yl)-4,4-dimethyl-1-penten-3-one in 49.7 g of chlorobenzene was added at room temperature. The resulting mixture was stirred at the same temperature for 18 hours. The reaction solution was decomposed with addition of 17.50 g of 10% hydrochloric acid and 5 g of water, and the organic layer was separated, washed with water and concentrated under reduced pressure to obtain 8.15 g (+)-(E)-1-(4-chlorophenyl)-2-(1,2,4-triazol-1-yl)-4,4-dimethyl-1-penten-3-ol as a crystal. The conversion was 99.8%, and the composition of the product obtained was: E-form alcohol, 90.8%; saturated alcohol, 2.3%; and Z-form alcohol, 6.9%. The enantiomer ratio of the E-form alcohol was: (+)-isomer, 81.0% and (-)-isomer, 19.0%. The optical yield was 62.0%.

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