反应详情

To a solution of methyl acetate (383 mg, 0.41 mL, 5.17 mmol) in anhydrous THF (10 mL) at −78° C. under N2 atmosphere is added 2 M LDA solution in THF (3.4 mL, 6.8 mmol) dropwise, and the solution is stirred another 30 min at the same temperature after the addition. To this mixture is added TiCl(OiPr)3 (1.681 g, 6.45 mmol) dropwise. The mixture is then stirred another 30 min at −78° C. To this mixture is added a solution of N-(6-bromo-2-phenylchroman-4-ylidene)-2-methylpropane-2-sulfinamide (1.050 g, 2.58 mmol) in anhydrous THF (10 mL) dropwise within 30 min. The reaction mixture is stirred another 3 h at −78° C. then quenched with sat. aq. NH4Cl. The mixture is stirred 10 min after being warmed to rt and filtered through a pad of Celite, and washed with EA (80 mL). The filtrate is transferred to separating funnel and the separated organic phase is washed with brine, and dried over anhydrous Na2SO4, filtered and concentrated, and the residue is purified through chromatography on silica gel to afford methyl 2-(6-bromo-4-(1,1-dimethylethylsulfinamido)-2-phenylchroman-4-yl)acetate 427 mg as an oil. MS ESI+ve m/z 480 (M+H)+.

1. additionafter the addition
2. stirringThe mixture is then stirred another 30 min at −78° C
3. stirringThe reaction mixture is stirred another 3 h at −78° C.
4. customthen quenched with sat. aq. NH4Cl
5. stirringThe mixture is stirred 10 min
6. filtrationfiltered through a pad of Celite
7. washwashed with EA (80 mL)
8. customto separating funnel
9. washthe separated organic phase is washed with brine
10. dry with materialdried over anhydrous Na2SO4
11. filtrationfiltered
12. concentrationconcentrated
13. customthe residue is purified through chromatography on silica gel