反应详情

To a solution of 2,4-difluoro-6-hydroxybenzaldehyde (1.0 g, 6.33 mmol) in THF (14 ml) were added (R)-(−)-pent-4-en-2-ol (1.090 g, 12.65 mmol) and triphenylphosphine (2.157 g, 8.22 mmol). To this mixture was added dropwise DIAD (1.599 ml, 8.22 mmol) (exotherm) and stirred at rt. After 20 h, the mixture was diluted with Et2O and washed with 1N NaOH followed by water (3×'s) then brine, dried (Na2SO4), filtered and concentrated. The crude was purified by flash chromatography (Biotage; 0%-50% EtOAc/hexane; 10 CV) to give (S)-2,4-difluoro-6-(pent-4-en-2-yloxy)benzaldehyde (0.3394 g, 1.500 mmol, 23.72% yield) as a pale yellow oil. 1H NMR (400 MHz, CDCl3) δ: 10.33 (s, 1H), 6.67-6.32 (m, 2H), 6.04-5.63 (m, 1H), 5.32-5.00 (m, 2H), 4.66-4.40 (m, 1H), 2.68-2.28 (m, 2H), 1.41 (d, J=6.1 Hz, 3H).

1. washwashed with 1N NaOH
2. dry with materialdried (Na2SO4)
3. filtrationfiltered
4. concentrationconcentrated
5. customThe crude was purified by flash chromatography (Biotage; 0%-50% EtOAc/hexane; 10 CV)