反应详情

To a solution of compound 15 (3 g, 7.3 mmol) and p-TsOH.H2O (0.3 g, 1.6 mmol) in toluene (150 mL) was heated to reflux for 1 h. The solution was washed with NaHCO3 solution and brine, dried over Na2SO4. After concentration, the residue was purified by column chromatography on silica gel (PE: EA=10:1) to give compound 16 (660 mg, 23.1%). 1H NMR (400 MHz, CDCl3) δ1.41 (s, 9 H), 3.04-3.07 (m, 1 H), 3.24-3.37 (m, 1 H), 3.39-3.41 (m, 1 H), 3.48-3.50 (m, 1 H), 3.74 (s, 3 H), 5.04 (bs, 1 H), 5.25 (bs, 1 H), 5.42 (bs, 1 H), 7.31-7.40 (m, 3H), 7.53-7.54 (m, 2H). MS (M+): 393. The stereochemistry was identified by NOE experiment.

1. temperatureto reflux for 1 h
2. washThe solution was washed with NaHCO3 solution and brine
3. dry with materialdried over Na2SO4
4. concentrationAfter concentration
5. customthe residue was purified by column chromatography on silica gel (PE: EA=10:1)