反应详情

To a solution of 4,5-difluoro-2-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). DIAD (1.599 ml, 8.22 mmol) was added dropwise (exotherm) and the mixture was stirred at rt. After 1.5 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 yellow oil was purified by flash chromatography (Biotage; 0%-100% EtOAc/hexane; 20 CV) to give (S)-4,5-difluoro-2-(pent-4-en-2-yloxy)benzaldehyde (0.1295 g, 0.572 mmol, 9.05% yield) as a yellow oil. 1H NMR (400 MHz, CDCl3) δ 10.36 (d, J=3.2 Hz, 1H), 7.76-7.55 (m, 1H), 6.83 (dd, J=11.9, 6.0 Hz, 1H), 6.04-5.67 (m, 1H), 5.23-5.06 (m, 2H), 4.48 (sxt, J=6.0 Hz, 1H), 2.71-2.35 (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 yellow oil was purified by flash chromatography (Biotage; 0%-100% EtOAc/hexane; 20 CV)