反应详情

To a solution of 6-bromo-3-fluoro-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (220 mg, 0.65 mmol) in anhydrous DCM was added TiCl4 (1 M in DCM, 1.4 mL) dropwise within 15 minutes at room temperature. After addition, the mixture was stirred for 1 h. To this mixture was added N,N′-methanediylidenebis(1,1,1-trimethylsilanamine) (264 mg, 1.42 mmol) dropwise. The resulting mixture was stirred for another 18 h after the addition. The reaction mixture was poured into ice-water and extracted with DCM. The combined organic phases were dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated to give crude product, which was used in the next step without further purification.

1. additionAfter addition
2. stirringThe resulting mixture was stirred for another 18 h
3. additionafter the addition
4. extractionextracted with DCM
5. dry with materialThe combined organic phases were dried over anhydrous Na2SO4
6. filtrationfiltered
7. concentrationthe filtrate was concentrated
8. customto give crude product, which
9. customwas used in the next step without further purification