反应详情

A 1.5 M solution of diisobutylaluminum hydride in toluene (6.0 mL, 9.0 mmol) was added dropwise to a stirred solution of compound [9a] (4.1 g, 7.2 mmol) in toluene (60 mL) at −70-−80° C. (acetone/dry ice bath) and the resulting mixture was stirred during 1 h at the same temperature. Methanol (10 mL) was added dropwise to the stirred mixture at −70-−80° C. The mixture was stirred for 1 hour at room temperature, filtered and evaporated under reduced pressure. Dichloromethane (30 mL) was added to the residue. The resulting solution was washed with brine (2×10 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (hexane/ethyl acetate 2:1 v/v) to obtain 2.0 g (49% yield) of the compound [10a]. 1H NMR (CDCl3) δ: 6.4-6.5 (m, 1H); 5.0-5.2 (m, 1H); 4.7-4.9 (m, 1H); 4.5-4.7 (m, 1H); 3.8-4.0 (m, 1H); 3.6-3.8 (m, 1H); 3.4-3.6 (m, 1H). 13C NMR (CDCl3) δ: 20.1; 25.5; 28.6; 31.3; 31.6; 36.7; 37.7; 40.3; 41.1; 46.2; 51.6; 63.0; 81.3; 82.0; 97.8; 100.2; 125.6; 127.1; 127.2; 128.1; 128.3; 128.4; 128.9; 129.2; 130.0; 130.1; 140.0; 145.7; 166.0. IR (KBr): 3500, 2945, 1712, 1605, 1278, 1117, 1026, 752 cm−1.

1. stirringThe mixture was stirred for 1 hour at room temperature
2. filtrationfiltered
3. customevaporated under reduced pressure
4. additionDichloromethane (30 mL) was added to the residue
5. washThe resulting solution was washed with brine (2×10 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. customevaporated under reduced pressure
9. customThe residue was purified by column chromatography on silica gel (hexane/ethyl acetate 2:1 v/v)