反应详情

温度

0 °C

A solution of 1 (o-nitrophenyl)-4-bromo-1-butanone (0.75 g, 2.75 mmol) in dry tetrahydrofuran (THF) under nitrogen is cooled to -78° C. with stirring, cautiously treated with 2.21 ml of 1.5M lithium diisopropylamide (LDA) in cyclohexane (3.3 mmol LDA), held at -78° C. for 1 hour, allowed to warm to 0° C. for 2 hours and poured onto a saturated NH4Cl solution. The resultant mixture is extracted with ethyl acetate. The extracts are combined, washed with brine, dried over Na2SO4 and concentrated in vacuo to give a residue. The residue is purified by flash column chromatography (silica gel; gradient 15%→25% ethyl acetate in hexane as eluent) to give the title product as a yellow oil, 0.34 g, 64% yield, identified by NMR and mass spectral analyses.

1. extractionThe resultant mixture is extracted with ethyl acetate
2. washwashed with brine
3. dry with materialdried over Na2SO4
4. concentrationconcentrated in vacuo
5. customto give a residue
6. customThe residue is purified by flash column chromatography (silica gel; gradient 15%→25% ethyl acetate in hexane as eluent)