反应详情

Under an argon atmosphere, a solution (80 ml) of Compound 45a (3.0 g) obtained in Step A in methylene chloride was cooled to −78° C., and then boron trifluoride ether complex (2.0 ml) and triethylsilane (3.9 ml) were succcessively added thereto, followed by stirring at room temperature for 3 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=20/1) to give Compound 45 (1.57 g, 54.7%) as colorless crystals.

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=20/1)