反应详情

温度

0 °C

Under an argon atmosphere, a solution (17 ml) of Compound 57a (0.6 g) obtained in Step A in methylene chloride was cooled to −78° C., and then boron trifluoride ether complex (0.42 ml) and triethylsilane (0.8 ml) were successively added thereto, followed by stirring at 0° C. for 2 hours. The reaction solution was poured into a saturated aqueous solution of sodium bicarbonate and the mixture was extracted with chloroform. The organic layer was washed with a saturated saline and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (chloroform/methanol=30/1) to give Compound 57 (0.042 g, 9.1%) as a pale-yellow oily substance.

1. extractionthe mixture was extracted with chloroform
2. washThe organic layer was washed with a saturated saline
3. dry with materialdried over anhydrous magnesium sulfate
4. distillationthe solvent was distilled off under reduced pressure
5. customThe residue was purified by silica gel column chromatography (chloroform/methanol=30/1)