反应详情

A solution of compound 458-A (1.96 g, 3.85 mmol) and diisopropylethylamine (806 μL, 4.61 mmol) in t-butanol (30 mL) was treated with DPPA (1.0 mL, 4.61 mmol) and refluxed for 6 h. The solvent was evaporated in vacuo, and the crude residue purified by flash column chromatography (SiO2), eluting with an ethyl acetate (10-35%) in heptane gradient, to afford compound 509-A (1.0 g, 45%) as a yellow amorphous solid. 1H-NMR (CDCl3): δ 1.48 (br s, 9H), 4.74 (s, 2H), 6.92-7.14 (m, 2H), 7.29-7.39 (m, 2H), 7.43-7.58 (m, 5H), 7.62-7.77 (m, 4H); MS: m/z 603.0 (MNa+).

1. temperaturerefluxed for 6 h
2. customThe solvent was evaporated in vacuo
3. customthe crude residue purified by flash column chromatography (SiO2)
4. washeluting with an ethyl acetate (10-35%) in heptane gradient