m-Chloroperbenzoic acid → 4,4-dimethyl-3,4-dihydro-2H-thiochromene-6-carbaldehyde 1-oxide
Reaction equation
[CH3:1][C:2]1([CH3:14])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:12]=[O:13])[CH:10]=2)[S:5][CH2:4][CH2:3]1.C1C=C(Cl)C=C(C(OO)=[O:23])C=1>ClCCl>[CH3:1][C:2]1([CH3:14])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:12]=[O:13])[CH:10]=2)[S:5](=[O:23])[CH2:4][CH2:3]1Participants
4
Procedure
4,4-Dimethyl-3,4-dihydro-2H-thiochromene-6-carbaldehyde (449 mg, 2.18 mmol, Example 5-28, Step 2) was dissolved in dichloromethane (22.0 mL) and mCPBA (751 mg, 4.35 mmol) was added in one portion. The reaction mixture was stirred at room temperature for 30 minutes. The mixture was then diluted with dichloromethane, washed with saturated aqueous NaHCO3, saturated aqueous NaCl, dried over Na2SO4, filtered and concentrated under vacuum. The crude mixture was purified by silica gel chromatography eluting with 0-5% MeOH/dichloromethane to afford the desired product as a colorless oil.