反应详情

A solution of 3 (1.14 g, 5.3 mmol) in acetone (15 mL) was added dropwise to a cold solution (ice bath) of CrO3 (3 g, 30 mmol) in sulfuric acid (23 mL) and water (67 mL). After the addition, the resulting solution was stirred in an ice bath for an additional 2 h and the solution was allowed to warm to room temperature overnight. TLC indicated the disappearance of the starting alcohol and the formation of one major spot at Rf=0.35 (hexane/EtOAc 2:1). The solution was extracted with 5×30 mL of ethyl ether and dried over Na2SO4. After evaporation of the solvent under reduced pressure, the resulting residue was flash chromatographed through silica gel column (3.5×15 cm) using hexane/EtOAc (2:1) as eluent. The desired fraction (TLC) was collected and the solvent was evaporated under reduced pressure to afford 570 mg of 4 as colorless oil. 1H NMR (DMSO-d6): δ 1.79-1.87 (m, 2H), 2.24-2.27 (t, J=7.2 Hz, 2H), 2.82-2.86 (t, J=7.2 Hz, 2H), 3.77 (s, 3H), 6.95-6.96 (d, J=3.6 Hz, 1H), 7.63-7.64 (d, J=3.6 Hz, 1H), 12.17 (br, 1H). HRMS calcd for C10H12O4S (M+), 228.0456; found: 228.0458.

1. additionAfter the addition
2. extractionThe solution was extracted with 5×30 mL of ethyl ether
3. dry with materialdried over Na2SO4
4. customAfter evaporation of the solvent under reduced pressure
5. customchromatographed through silica gel column (3.5×15 cm)
6. customThe desired fraction (TLC) was collected
7. customthe solvent was evaporated under reduced pressure