Methyl Acetate → Methyl 2-(6-bromo-4-(1,1-dimethylethylsulfinamido)-2-phenylchroman-4-yl)acetate

Participants

Reaction Steps

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)+.

Provenance & Evidence