3,4-dihydro-2H-pyran → 2-(4-(chloromethyl)benzyloxy)tetrahydro-2H-pyran

Participants

Reaction Conditions

Reaction Steps

p-Hydroxymethylbenzyl chloride (1.33 kg, 1 mole) in dichloromethane (6 liters) was charged to a 10 liter Morton flask. Addition of 3,4-dihydro-2H-pyran (925 g, 1.1 moles) to the flask was followed by cooling to 5° C. Pyridinium p-toluenesulfonate (1.25 g, 5 mmoles) was added as a catalyst. The contents were allowed to warm up to 20°-25° C. and stirred for 24 hours. The contents were washed with water followed by a sodium bicarbonate solution and then dried over anhydrous magnesium sulfate. The residue, after removal of solvent, was kept under high vacuum (1-2 mm Hg) for 24 hours and provided 2.28 kg (95% yield) of the desired product. 1H NMR spectral data were as follows: (CDCl3, 300 MHz): δ 7.4 (s, 4H), 4.75 (t, 1H), 4.65 (AB quartet, 2H, J=13 Hz), 4.6 (s, 2H), 3.85 (m, 1H), 3.55 (m, 1H), 1.5-1.95 (m, 6H).

Provenance & Evidence