反应详情

温度

95 °C

To a solution of tert-butyl N-tert-butoxycarbonyl-N-[(3S,7S,8R,9S)-8-hydroxy-9-methyl-7-(1-naphthylmethyl)-2-oxo-1,5-dioxonan-3-yl]carbamate (205 mg, 0.387 mmol), [Pd2(dba)3] (26.6 mg, 0.029 mmol), and dppf (32.5 mg, 0.058 mmol) in toluene (1.94 mL) was added (E) tert-butyl cyclopent-2-en-1-yl carbonate (250 mg, 1.355 mmol), and the mixture was warmed to 95° C. and stirred for 2 h. An additional portion of (E)-tert-butyl pent-2-en-1-yl carbonate (150 mg, 0.6 equiv.) was added to the reaction and stirring continued for an additional 2 h. The mixture was cooled to room temperature and the toluene was removed under reduced pressure. The residue was dissolved in CH2Cl2 (12 mL), adsorbed to Celite® and purified by flash chromatography (SiO2, 35 mL/min, 0→25 EtOAc/hexanes) to provide tert-butyl N-tert-butoxycarbonyl-N-[(3S,7S,8R,9S)-8-cyclopent-2-en-1-yloxy-9-methyl-7-(1-naphthylmethyl)-2-oxo-1,5-dioxonan-3-yl]carbamate (205 mg, 89%) as a mixture of diastereomers (about 1:1) in the form of a white solid: IR (thin film) 2928, 1755, 1709, 1117 cm−1; 1H NMR (400 MHz, CDCl3) δ 8.09 (m, 1H), 7.82 (m, 1H), 7.74-7.66 (m, 1H), 7.53-7.39 (m, 2H), 7.42-7.28 (m, 2H), 6.13-6.01 (m, 1.5H), 6.01-5.92 (m, 0.5H), 5.07 (app t, J=7.7 Hz, 1H), 4.90-4.79 (m, 2H), 4.02-3.83 (m, 2H), 3.76 (dd, J=13.6, 2.8 Hz, 1H), 3.55-3.39 (m, 3H), 2.82-2.66 (m, 1H), 2.60-2.47 (m, 1H), 2.34-2.17 (m, 2H), 2.11-1.92 (m, 3H), 1.57 (app dd, J=12.6, 6.4 Hz, 3H), 1.39 (app d, J=5.9 Hz, 18H); ESIMS m/z 618 ([M+Na]+).

1. stirringstirring
2. waitcontinued for an additional 2 h
3. temperatureThe mixture was cooled to room temperature
4. customthe toluene was removed under reduced pressure
5. dissolutionThe residue was dissolved in CH2Cl2 (12 mL)
6. custompurified by flash chromatography (SiO2, 35 mL/min, 0→25 EtOAc/hexanes)