p-Toluenesulfonic acid → 2H-Pyran, tetrahydro-2-[(2-methyl-3-nitrophenyl)methoxy]-

Participants

Reaction Steps

A solution of 100 g (0.598 mol) of 2-methyl-3-nitrophenylmethanol, 75.5 g (0.897 mol) of dihydropyran, and 15.0 g (0.06 mol) of the pyridinium salt of 4-methylbenzenesulfonic acid in 1 L of methylene chloride was stirred at ambient temperature for 24 hours. The reaction mixture was washed with two portions of 200 mL each of a saturated aqueous solution of sodium chloride, dried with magnesium sulfate, filtered, and the filtrate concentrated under reduced pressure to give a residual oil. The oil was subjected to column chromatography on silica gel, eluting with methylene chloride. The appropriate fractions were combined and concentrated under reduced pressure to give a residual oil. The oil was dissolved in 1 L of toluene, and was stirred in a Morton flask for 19 hours in the presence of 5 g of powdered Raney nickel. The mixture was filtered, and the filtrate concentrated under reduced pressure to give 147.8 g of 3-nitro-2-methylbenzenemethanol tetrahydropyranyl ether.

Provenance & Evidence