反应详情

2-Benzyloxy-benzenesulfonyl chloride (see Example 23, step 1) (1.7 g, 6 mmol) and (S)-3-amino-4,4-diethoxy-butyric acid tert-butyl ester (see Example 93) (1.5 g, 6 mmol) and pyridine (1.9 g, 30 mmol) were dissolved in chloroform (150 mL) and stirred at room temperature for 3 days. The reaction was diluted with ethyl acetate (500 mL) and washed with 5% citric acid, sat. sodium bicarbonate, and sat. sodium chloride. The organic layer was then dried over anhydrous sodium sulfate, filtered, and concentrated. Purification by flash chromatography (SiO2, hexane:ethyl acetate, 8:1, then 4:1) gave the desired product (2.7 g, 91%) as a colorless oil. 1H NMR (400 MHz) CDCl3 δ 7.92 (m, 1H), 7.52 (d, 2H), 7.47 (t, 1H), 7.40 (t, 2H), 7.34 (d, 1H), 7.04 (t, 2H), 5.61 (d, 1H), 5.23 (q, 2H), 4.30 (d, 1H), 3.77 (m, 1H), 3.47 (m, 2H), 3.36 (m, 1H), 3.15 (m, 1H), 2.45 (t, 2H), 1.37 (s, 9H), 1.02 (t, 3H), 0.92 (t, 3H).

1. washwashed with 5% citric acid, sat. sodium bicarbonate, and sat. sodium chloride
2. dry with materialThe organic layer was then dried over anhydrous sodium sulfate
3. filtrationfiltered
4. concentrationconcentrated
5. customPurification by flash chromatography (SiO2, hexane