反应详情

Trimethyloxonium tetrafluoroborate (2.0 g, 13.5 mmol, 1.2 equiv) and 2,6-di-tert-butylpyridine (1.52 mL, 6.76 mmol, 0.6 equiv) were added to a solution of d1 (3.36 g, 11.26 mmol, 1 equiv) in CH2Cl2 (80 mL) at 23° C. The reaction mixture was stirred at that temperature for 65 h, then was partitioned between water (2×50 mL) and CH2Cl2 (2×200 mL) and combined organic layers were dried over Na2SO4 and concentrated. The residue was purified by flash column chromatography (5% EtOAc in hexanes) to afford e1 (3.19 g, 91%) as colorless oil: IR (cm−1) 3432, 1733; 1H NMR (CDCl3) δ 2.42-2.49 (m, 2H), 2.73 (t, 2H, J=7.6), 3.96 (s, 3H), 4.94-5.07 (m, 2H), 5.20 (s, 2H), 5.80-5.94 (m, 1H), 6.71 (d, 1H, J=7.9), 7.11 (s, br, 1H), 7.32-7.43 (m, 5H), 8.16 (s, br, 1H); Anal. C18H20N2O3: C, H, N.

1. customwas partitioned between water (2×50 mL) and CH2Cl2 (2×200 mL)
2. dry with materialwere dried over Na2SO4
3. concentrationconcentrated
4. customThe residue was purified by flash column chromatography (5% EtOAc in hexanes)