反应详情

温度

-10 °C

A 100 ml three-necked flask was charged with anhydrous THF (20 mL), (R) -MeCBS catalyst (0.325 mL, 1 M, 0.325 mmol), and BH3-THF (6.49 mL, 1M, 6.49 mmol) under nitrogen. The solution was cooled to −10° C. and 3-(1,3-benzodioxol-5yl)-6-propoxy-1H-inden-1-one (2.0 g, 6.49 mmol) in anhydrous THF (20 mL) was added dropwise over 2 h period. After 45 minutes a solution of Et3N (2.0 mL, 14.3 mmol) and MeOH (1.3 mL, 19.5 mmol) was added cautiously while maintaining the internal temperature below −5° C. The reaction mixture was concentrated in vacuo and purified via flash chromatography (EtOAc/hexane, 1:3) affording (S)-3-(1,3-benzodioxol-5-yl)-6-propoxy-1H-inden-1-ol as a yellow oil (1.9 g, 95%, 94% e.e.); Chiralcel OC column (90:10 IPA/hexane, 2 mL/min, 254 nm): 13.321 min (2.34%) :16.031 min (85.23%); 1H NMR (CDCl3) δ7.30 (d, J=8.3 Hz, 1H), 7.2 (s, 1H), 7.1-7.0 (m, 2H), 6.9 (d, J=8.0 Hz, 1H), 6.8 (dd, J=8.4, 2.4 Hz, 1H), 6.25 H), 6.0 (s, 2H), 5.2 (d, J=7.2 Hz, 1H), 3.95 (t, J=6.6 Hz, 3H), 1.85 (m, 2H), 1.0 (t, J=, 3H).

1. temperaturewhile maintaining the internal temperature below −5° C
2. concentrationThe reaction mixture was concentrated in vacuo
3. custompurified via flash chromatography (EtOAc/hexane, 1:3)