反应详情

Compound 22.3 (2.03 g, 4.93 mmol) in anhydrous dimethyl sulfoxide (25 mL, 0.2 M) was treated with dichloroacetic acid (400 μL, 4.93 mmol) and DCC (2.04 g, 9.67 mmol). The solution was stirred at room temperature for 2 h. [(Diethoxyphosphinyl)methylidene]triphenylphosphorane (2.0 g, 4.93 mmol, J. Org. Chem. 1996, 61, 7697-7701) was added and the mixture was stirred overnight. MeOH (25 mL) and H2O (25 mL) were added and the mixture was filtered over a plug of SiO2 and washed with MeOH (3×25 mL). The solvent was removed in vacuo and residue was suspended in CH2Cl2 and filtered over a plug of SiO2, and the solvent removed in vacuo. The residue was subjected to a column chromatography eluting with 0-100% EtOAc-hexanes, followed by 0-20% MeOH—CH2Cl2 to afford compound 22.4 (734 mg, 27% yield, E/Z ratio not determined) as a white solid (data for major isomer): 1H NMR (CDCl3, 300 MHz) 9.73 (br s, 1H), 8.71 (s, 2H), 7.91 (d, J=7.8 Hz, 2H), 7.50 (m, 1H), 7.35 (t, J=7.5 Hz, 2H), 6.89 (m, 1H), 6.15 (br s, 1H), 5.95 (m, 1H), 4.78 (m, 1H), 4.62 (m, 1H), 4.36 (m, 1H), 4.01 (m, 4H), 1.23 (m, 12H); 31P NMR (DMSO-d6, 121.4 MHz) 15.9; MS (ESI) m/z 544 [M+H+].

1. additionwas added
2. filtrationthe mixture was filtered over a plug of SiO2
3. washwashed with MeOH (3×25 mL)
4. customThe solvent was removed in vacuo and residue
5. filtrationfiltered over a plug of SiO2
6. customthe solvent removed in vacuo
7. washeluting with 0-100% EtOAc-hexanes