反应详情

To a mixture of the compound (6.9 g) obtained in Example 63 and methylene chloride (70 ml) were added t-butanol (20 ml), N,N-dimethylaminopyridine (2.63 g) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (4.9 g) and the resulting mixture was stirred at room temperature for 4 days. The reaction mixture was diluted with ethyl acetate and washed successively with 2 N HCl and a saturated aqueous sodium chloride solution; the organic layer was dried with anhydrous sodium sulfate and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent, n-hexane:ethyl acetate=3:1) to give 7.64 g of the titled compound (yield, 97%).

1. washwashed successively with 2 N HCl
2. dry with materialthe organic layer was dried with anhydrous sodium sulfate
3. distillationthe solvent was distilled off under reduced pressure
4. customThe resulting residue was purified by silica gel column chromatography (eluent, n-hexane:ethyl acetate=3:1)