反应详情

To a vigorously stirred solution of 1.05 g (3.75 mmol) of dimethyl 3-(phenylthio)cyclobutane-1,2-dicarboxylate from Step A in 20 mL of methanol, was added slowly a suspension of 3.46 g (11.25 mmol) of OXONE (a commercially available mixture of sulfuric acid potassium salt and potassium hydrogen peroxymonosulfate) in 20 mL of water. The resultant cloudy suspension was stirred for 0.5 h then diluted with 50 mL of water and 100 mL of 1,2-dichloroethane. The phases were allowed to separate and the aqueous phase was extracted with 20 mL of 1,2-dichloroethane. The combined organic layers were washed with 2×50 mL of dilute aqueous sodium bicarbonate solution, 2×50 mL of water and 50 mL of brine, dried over anhydrous magnesium sulfate and concentrated to give 1.10 g (94% yield) of the title compound as a viscous oil; EI-MS, m/e (relative intensity): 281 (M+ -OCH3, 9), 171 (100), 139 (24), 111 (47); 1H NMR (CDCl3) δ 2.48 (m, 1H), 2.76 (m, 1H), 3.23 (q, 1H), 3.52 (s, 3H), 3.74 (s, 3H), 3.80 (m, 1H), 3.92 (q, 1H), 7.58 (m, 2H), 7.68 (m, 1H), 7.89 (m, 2H).

1. customto separate
2. extractionthe aqueous phase was extracted with 20 mL of 1,2-dichloroethane
3. washThe combined organic layers were washed with 2×50 mL of dilute aqueous sodium bicarbonate solution, 2×50 mL of water and 50 mL of brine
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationconcentrated