Dichloromethane → 8-Acetoxy-6-bromo-2,2,4,4-tetramethyl chroman

Participants

Reaction Steps

A solution of 8-acetyl-6-bromo-2,2,4,4-tetramethyl chroman (Intermediate 15A, 1.3 g, 4.18 mol) in anhydrous dichloromethane (30 mol) was treated with a 77% aqueous solution of 3-chloroperoxybenzoic acid (5.75 g, 33.44 mmol) and the resulting reaction mixture was stirred at ambient temperature for 24 h. The reaction mixture was then cooled in an ice bath and cautiously quenched with saturated sodium thiosulfate solution. The phases were separated and the organic phase was washed with saturated, aqueous sodium bicarbonate solution, water and brine, dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to afford a residue that on flash column chromatography over silica gel (230-400 mesh) using 10% ethyl acetate in hexane as the eluent afforded the title compound as an oil (1.3 g, 92%).

Provenance & Evidence