反应详情

A solution of the product of STEP 4 (0.79 g) and dichloromethane (15 ml) was cooled to 0° C. A 1 M solution of boron tribromide in dichloromethane (6.00 ml) was added slowly. The solution was stirred at room temperature for 1 hour. Ethanol (5 ml) was added to quench the reaction. Solvent was removed. Residue was extracted with 1% of hydrochloric acid aqueous solution and ethyl acetate. The organic extract was washed with saturated sodium bicarbonate/water, and then dried over MgSO4. Solvent was removed. The crude product was purified on a silica gel column, eluting with 20% ethyl acetate/hexane to afford colorless oil (0.32 g). The 1H NMR was consistent with the proposed structure.

1. customto quench
2. customthe reaction
3. customSolvent was removed
4. extractionResidue was extracted with 1% of hydrochloric acid aqueous solution and ethyl acetate
5. extractionThe organic extract
6. washwas washed with saturated sodium bicarbonate/water
7. dry with materialdried over MgSO4
8. customSolvent was removed
9. customThe crude product was purified on a silica gel column
10. washeluting with 20% ethyl acetate/hexane