Heptane → 7-bromo-3,4-dihydro-2H-1-benzopyran-4-one

Participants

Reaction Steps

A solution of diisobutylaluminum hydride in heptane (1.0 M, 60 mL, 60.0 mmol) was added dropwise to a solution of 7-bromo-4H-chromen-4-one (4.5 g, 20.0 mmol) in tetrahydrofuran at −78° C. under an atmosphere of argon over a period of 30 minutes. After 30 minutes the reaction was quenched with a mixture of silica gel (10 g), and water (10 mL). The mixture was allowed to warm to room temperature and was filter through celite and the tetrahydrofuran was removed under reduced pressure. The residue was taken up in chloroform (100 mL) and washed with sodium hydroxide (1N, 25 mL) and dried over sodium sulfate. The mixture was filtered and the solvent was removed under reduced pressure. The residue was subjected to flash chromatography with eluant of dichloromethane. The product containing fractions were combined and the solvent was removed under reduced pressure to provide 7-bromochroman-4-one (3.57 g, 15.7 mmol, 78%).

Provenance & Evidence