反应详情

To a suspension of triacetoxyborohydride (Aldrich) (21 g, 10 mmol) in dry THF (220 mL), a solution in dry THF (40 mL) of 4-(3′-nitrophenyl)-4-oxo-2-butenoic acid (2.2 g, 10 mmol)(prepared as described in example 7,(mp. 178-179° C.)), was added on stirring at room temperature, under dry nitrogen atmosphere. The resulting light yellow solution was stirred at room temperature overnight under nitrogen atmosphere. To the colorless reaction mixture, aqueos 1N HCl (50 mL), was slowly added dropwise, on cooling at 0° C. The most of the solvent was evaporated under reduced pressure and the residue taken up with 2N HCl and extracted with the ethyl acetate. The combined organic extracts were washed with brine, dried and concentrated in vacuo, to led to a solid. Recrystallization from diethyl ether/hexane afforded a cream solid (1.7 g ,77%), mp. 162-164° C.

1. stirringThe resulting light yellow solution was stirred at room temperature overnight under nitrogen atmosphere
2. temperatureon cooling at 0° C
3. customThe most of the solvent was evaporated under reduced pressure
4. extractionextracted with the ethyl acetate
5. washThe combined organic extracts were washed with brine
6. customdried
7. concentrationconcentrated in vacuo
8. customRecrystallization from diethyl ether/hexane