反应详情

A solution of 1,3-dithiane (14.1 g, 117 mmol) in THF (100 mL) was treated with n-BuLi (44.9 mL, 112 mmol, 2.5M in hexane) at 0° C. for 1 hour, followed by the addition of a solution of the above aldehyde 95 in THF (20 mL) at −50° C. After kept additional 1 hour at 0° C., the reaction was quenched by saturated aqueous NH4Cl (150 mL) and extracted with ethyl acetate (3×80 mL). The combined organic layer was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give a residue, which was purified by a silica gel column, eluted with 20%-50% ethyl acetate in petroleum to afford the title compound as a yellow syrup (6.4 g, 62%, two epimers' ratio is 1:1 by 1H NMR); (ES, m/z) [M+H]+ 547.0; 1H NMR (300 MHz, CDCl3) δ 7.28-7.44 (m, 10H), 6.33 (d, J=6.6 Hz, 1H), 4.63-4.84 (m, 4H), 4.52-4.58 (m, 1H), 4.12-4.15 (m, 1H), 3.98-4.05 (m, 3H), 3.82-3.85 (m, 1H), 2.99 (s, 6H), 2.80-2.87 (m, 1H), 2.61-2.68 (m, 3H), 1.65-1.69 (m, 2H).

1. customthe reaction was quenched by saturated aqueous NH4Cl (150 mL)
2. extractionextracted with ethyl acetate (3×80 mL)
3. dry with materialThe combined organic layer was dried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customto give a residue, which
7. customwas purified by a silica gel column
8. washeluted with 20%-50% ethyl acetate in petroleum