反应详情

温度

-10 °C

62 ml (10 equiv.) hydrazine hydrate was added to 150 mL diethylether. The emulsion was cooled with an ice/NaCl bath to −10° C. A solution of 20.4 g 2-benzylidene-butyraldehyde in 100 mL ether was added dropwise at −10° C. and stirred at −10° C. for 3 hours. The mixture was stirred overnight (with ice bath) and allowed to slowly reach room temperature. H2O was added, the organic layer was separated and the aqueous layer was extracted 2 times with diethylether. The combined organic layers were dried over Na2SO4, filtrated and concentrated in vacuo. Vacuum destillation yielded 6.1 g of a clear fluid (102-106° C., 0.6 mbar) containing 94% of the desired product (mixture of diastereomeric pairs). Characteristic signals of the first diastereomeric pair: 1H NMR (400 MHz, CDCl3) δ 0.83 (t, J=6.5 Hz, 3H), 3.03-3.13 (m, 1H), 4.74-4.81 (m, 1H), 6.83 (br s, 1H). Characteristic signals of the second diastereomeric pair: 1H NMR (400 MHz, CDCl3) δ 1.00 (t, J=7.5 Hz, 3H), 2.84-2.93 (m, 1H), 4.28-4.34 (m, 1H), 6.76 (br s, 1H).

1. stirringThe mixture was stirred overnight (with ice bath)
2. customallowed to slowly reach room temperature
3. customthe organic layer was separated
4. extractionthe aqueous layer was extracted 2 times with diethylether
5. dry with materialThe combined organic layers were dried over Na2SO4
6. filtrationfiltrated
7. concentrationconcentrated in vacuo
8. customVacuum destillation yielded 6.1 g of a clear fluid (102-106° C., 0.6 mbar)