反应详情

A solution of 7a (8.34 g, 20 mmol) in aqueous THF (60 mL, 1:1) was treated with concentrated H2SO4 (10 mL) and stirred at room temperature for 24 h. The mixture was concentrated under vacuum, diluted with water, and the aqueous layer was extracted with CHCl3. The combined organic layer was washed with H2O , dried (NaSO4) and concentrated. The residue was purified by flash column chromatography over silica gel with EtOAc/hexane (2:1) as eluant to give 8b (2.50 g, 88%) as an oil; IR (neat) 3452 (OH), 1777 (C=O), 1641 cm-1 ; 1H NMR (CDCl3) δ 2.51 (d of AB, J=17.4 Hz, 1 H, H-3a), 2.63 (d of AB, J=17.4 Hz, 1 H, H-3b), 3.62 (s, 2 H, CH2OH), 4.16 (d of AB, J=9.2 Hz, 1 H, H-5a), 4.32 (d of AB, J=9.2 Hz, 1 H, H-5b), 5.19 (d, J=17.5 Hz, 1 H, CH=CHH), 5.29 (d, J=10.8 Hz, 1 H, CH=CHH), 5.85 (dd, J=17.5, 10.8 Hz, 1 H, CH=CH2); 13C NMR (CDCl3) δ 35.94, 47.61, 65.56, 73.33, 116.18, 137.55, 176.97. Anal. Calcd for C7H10O3 : C, 59.14; H. 7.09. Found: C, 59.05; H, 7.09.

1. concentrationThe mixture was concentrated under vacuum
2. additiondiluted with water
3. extractionthe aqueous layer was extracted with CHCl3
4. washThe combined organic layer was washed with H2O
5. dry with materialdried (NaSO4)
6. concentrationconcentrated
7. customThe residue was purified by flash column chromatography over silica gel with EtOAc/hexane (2:1) as eluant