4-Bromophenol → 2-(4-Bromophenoxy)tetrahydro-2H-pyran

Participants

Reaction Steps

Using the same general procedure as for the preparation of 4-bromo-2-t-butyl-1-(2-tetrahydropyranoxy)benzene (Compound H), but instead using 15.00 g (86.7 mmol) of 4-bromophenol, 2.18 g (8.7 mmol) of pyridinium p-toluenesulfonate and 10.94 g (11.9 ml, 130.1 mmol) of 3,4-dihydro-2H-pyran and 75 ml of dichloromethane produced a clear, slightly yellow oil. Purification by flash chromatography (silica, 5% ethyl acetate in hexane) yielded a mixture of 4-bromophenol and the desired THP-ether. This mixture was separated by diluting with 300 ml of 1N aqueous NaOH solution, stirring at room temperature followed by ether extraction. The organic phase was dried over K2CO3, filtered and concentrated in vacuo to give the title compound as a white solid. PMR (CDCl3): d 1.5-2.1 (6H, m), 3.5-3.7 (1H, m), 3.8-3.95 (1H, m), 5.37 (1H, t, J=3.2 Hz), 6.9-6.96 (2H, m), 7.34-7.39 (2H, m).

Provenance & Evidence