反应详情

To a solution of 32 (1.52 g, 4.39 mmol) in CH2Cl2 (50 mL) were added triphenylphosphine (1.32 g, 5.033 mmol) and imidazole (0.45 g, 6.61 mmol). The reaction mixture was cooled to 0° C., before the addition of iodine (1.22 g, 4.81 mmol). The mixture was then removed from the cooling bath, stirred for 2 h, diluted with hexanes (100 mL) and filtered washing the precipitate with further hexanes (2×30 mL). The filtrate was evaporated and purified by flash chromatography on silica gel with gradient elution from 0-10% methanol/ethyl acetate to give pure 33 (1.6 g, 80%). 1H NMR (400 MHz, CDCl3) δ 1.32-1.38 (m, 12H), 1.95-2.15 (m, 4H), 2.28 (tt, J=24.1, 6.1, 1H), 3.18 (t, J=6.6, 2H), 4.12-4.24 (m, 8H).

1. customThe mixture was then removed from the cooling bath
2. additiondiluted with hexanes (100 mL)
3. filtrationfiltered
4. washwashing the precipitate with further hexanes (2×30 mL)
5. customThe filtrate was evaporated
6. custompurified by flash chromatography on silica gel with gradient elution from 0-10% methanol/ethyl acetate