7-Tert-butyl-chroman-4-ol → 7-(Tert-butyl)chroman-4-one

Participants

Reaction Steps

The crude 7-tert-butyl-chroman-4-ol from step B was dissolved in 50 ml dichloromethane. Pyridinium chlorochromate (4.31 g, 20 mmol) was added and the reaction mixture was stirred at ambient temperature for 3 hours, diluted with hexanes and filtered through a pad of celite. Solvent was removed from the filtrate under reduced pressure and the residue filtered through a pad of silica gel, eluting with 20% ethyl acetate:hexanes. Removal of solvent gave 2.37 g of crude product, which was chromatographed on silica gel with an eluent of 10% ethyl acetate: hexanes to give 1.50 g of the title compound (73% for 3 steps). 1H NMR (300 MHz, CDCl3) δ 7.83 (d, 1H, J=8.1 Hz), 7.07 (dd, 1H, J=8.3 and 1.9 Hz), 6.97 (d, 1H, J=1.7 Hz), 4.62 (m, 2H), 2.78 (m, 2H), 1.31 (s, 9H). MS (DCI) m/e 205 (M+H)+.

Provenance & Evidence