4-Toluenesulfonyl chloride → (3,4-dihydro-2H-pyran-2-yl)methyl 4-methylbenzene-1-sulfonate

Participants

Reaction Steps

Whilst cooling a solution of 14.2 g of 2-hydroxymethyl-3,4-dihydro-2H-pyran in 120 ml of pyridine on an ice-water bath at 0°-5° C., 28.4 g of crystals of tosyl chloride were added and the mixture was then stirred at room temperature overnight. The salt which precipitated with the aid of a Celite (Trademark) filter aid was separated by filtration and the filtrate was concentrated under reduced pressure. Water was added to the residue and the resulting mixture was extracted with diethyl ether. The ethereal extract was washed with a saturated aqueous solution of sodium bicarbonate and then with aqueous sodium chloride, after which the solvent was evaporated off under reduced pressure. The residue was purified by column chromatography through silica gel eluted with a 7:1 by volume mixture of hexane and ethyl acetate, to give 31.5 g of the title compound, in the form of colourless crystals melting at 47°-48° C.

Provenance & Evidence