反应详情

To a solution of (+)-N-((3R)-3-(4-isopropylphenyl)-7-methoxy-4,6-dimethyl-2,3-dihydro-1-benzofuran-5-yl)-3,3-dimethylbutanamide (500 mg, 1.22 mmol) obtained in Example 52 in dichloromethane (20 mL) was added dropwise at −78° C. under an argon atmosphere boron tribromide (1.0 M dichloromethane solution, 3.0 mL, 3.0 mmol). The reaction solution was warmed to room temperature, added to an aqueous saturated sodium hydrogen carbonate solution, and extracted with ethyl acetate. The combined organic layers were washed with saturated brine, dried over sodium sulfate, filtered, and then concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:2) to synthesize 378 mg (yield: 78%) of the title compound. Melting point: 202-203° C. (ethyl acetate-hexane). [α]D20=+79.00 (c=0.49, chloroform).

1. extractionextracted with ethyl acetate
2. washThe combined organic layers were washed with saturated brine
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe obtained residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:2)