3,4-dihydro-2H-pyran → 5-Bromo-2-t-butyl-1-(2-tetrahydropyranoxy)benzene

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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 8.18 g (35.7 mmol) of 5-bromo-2-t-butylphenol (Compound D), 0.90 g, 3.6 mmol) of pyridinium p-toluenesulfonate and 4.50 g (4.9 ml, 53.6 mmol) of 3,4-dihydro-2H-pyran and 50 ml of dichloromethane stirred at room temperature for 21 hours produced a dark yellow solution. At this time an additional 1.80 g (7.2 mmol) of pyridinium p-toluenesulfonate was added to the solution and it was allowed to stir at room temperature for 19 hours. After aqueous workup, a clear, yellow oil was isolated. Purification by flash chromatography (silica, 5% ethyl acetate in hexane) yielded the title compound as a clear, slightly yellow oil. PMR (CDCl3):d 1.38 (9H, s), 1.6-2.1 (6H, m), 3.65-3.75 (1H, m), 3.8-3.95 (1H, m), 5.45 (1H, t, J=2.5 Hz), 7.03 (1H, dd, J=8.4, 2..0 Hz), 7.13 (1H, d, J=8.4 Hz), 7.33 (1H, d, J=2.0 Hz).

Provenance & Evidence