反应详情

To NaH (1.85 g, 60% dispersed in mineral oil) under argon was added anhydrous N, N-dimethylformamide (DMF, 30 mL) at RT. Solketal (2.20 g, 16.7 mmol) in 10 mL anhydrous DMF was then added dropwise with constant stirring. 1-Bromohexadecane (5.10 g, 16.7 mmol), dissolved in anhydrous DMF (20 mL) was then added to the reaction mixture dropwise and stirred for 72 hours. The reaction was quenched by adding about 5 mL of methanol. It was then poured into cold ice water (100 mL) and extracted with hexane (100 mL, 3×). The solvent was removed under reduced pressure and the residue chromatographed on silica gel using hexane-dichloromethane to obtain 1a (3.363 g, 57% yield); 1H NMR (in CDCl3): δ in ppm 0.83-0.86 (3H, t, J=6.5 Hz), 1.22 (26H, m), 1.33 (3H, s), 1.39 (3H, s), 1.52-1.55 (2H, m), 3.37-3.48 (4H, m), 3.68-3.71 (1H, t, J=6.5 Hz), 4.01-4.03 (1H, t, J=6.5 Hz), 4.20-4.25 (1H, quintet, J=6.0 Hz); 13C NMR (in CDCl3): 8 in ppm 14.3, 22.9, 25.6, 26.2, 27.0, 29.6, 29.7, 29.8, 29.9, 32.1, 67.1, 72.0, 72.1, 74.9, 109.5.

1. additionwas then added to the reaction mixture dropwise
2. customThe reaction was quenched
3. additionby adding about 5 mL of methanol
4. additionIt was then poured into cold ice water (100 mL)
5. extractionextracted with hexane (100 mL, 3×)
6. customThe solvent was removed under reduced pressure
7. customthe residue chromatographed on silica gel