Acetic Acid → 4-bromo-2-(4-bromophenyl)tetrahydro-2H-pyran

Participants

Reaction Steps

To a solution of 4-bromobenzaldehyde (1.00 g, 5.41 mmol) and 3-buten-1-ol (800 mg, 10.8 mmol) in dichloromethane (20 mL) at room temperature was added zinc (II) bromide (25 mg, 0.11 mmol) followed by 33% hydrobromic acid (2.4 g) in acetic acid (4.9 g, 81 mmol) and stirred at room temperature for 5 hours. Reaction was quenched by aqueous sodium bicarbonate, then extracted with ethyl acetate, washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography to give the title compound (1.00 g) which contained some of 4-bromobenzaldehyde 1H NMR (400 MHz, CDCl3) δ ppm 7.49 (d, 2H) 7.24 (d, 2H) 5.19 (dd, 1H) 4.25 (m, 1H) 4.12 (m, 1H) 3.60 (m, 1H) 2.75 (m, 1H) 2.68 (m, 1H) 2.11 (m, 2H).

Provenance & Evidence