[F:1][C:2]1([F:11])[O:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[O:3]1.C1CCCCC1.[Li]C(CC)C.C[O:24][B:25](OC)[O:26]C>C1COCC1>[F:11][C:2]1([F:1])[O:3][C:4]2[CH:10]=[CH:9][CH:8]=[C:7]([B:25]([OH:26])[OH:24])[C:5]=2[O:6]12,2-Difluoro-1,3-benzodioxole (960 mg, 6.1 mmol) was dissolved in THF (8 mL) and cyclohexane (4 mL) and the resulting solution cooled to −78° C. sec-BuLi 1.4M solution in cyclohexane (4.3 mL, 6.1 mmol) was added dropwise and the reaction mixture stirred for 1.5 hours at −78° C. Trimethylborate (694 mg, 6.75 mmol) was added and the mixture was allowed to warm slowly to −30° C. The reaction mixture was quenched with a 2N solution of HCl and diluted with ethyl acetate. Two phases were separated and the organic layer was washed twice with brine, dried over Na2SO4 and evaporated to dryness affording the title compound as yellow oil which was used in the next step without further purification.
불러오는 중…