反应详情

n-Butyllithium in hexane (1.53M, 113.5 ml) was added dropwise to N,N-diisopropylamine (17.9 g) in THF (100 ml) at -78° under nitrogen. The mixture was warmed to 0°, stirred for 1 h and treated dropwise with isobutyric acid (7.65 g) in THF (20 ml). The resulting suspension was stirred at room temperature for 3 h, and the product of stage (ii) (20.0 g) was added dropwise. The reaction mixture was stirred for 16 h at room temperature and the solvent was evaporated. The resultant oil was partitioned between EA (250 ml) and water (250 ml). The aqueous layer was acidified to pH 6 with 2N aqueous hydrochloric acid and the organic extract was separated. The aqueous layer was extracted with EA (250 ml) and the combined extracts were concentrated to leave the title compound as an orange oil (20.4 g). T.l.c. (ER) Rf 0.53.

1. temperatureThe mixture was warmed to 0°
2. stirringThe resulting suspension was stirred at room temperature for 3 h
3. stirringThe reaction mixture was stirred for 16 h at room temperature
4. customthe solvent was evaporated
5. customThe resultant oil was partitioned between EA (250 ml) and water (250 ml)
6. extractionthe organic extract
7. customwas separated
8. extractionThe aqueous layer was extracted with EA (250 ml)
9. concentrationthe combined extracts were concentrated