Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → (1R)-1-[2-(2,4-difluorophenyl)-2-oxiranyl]ethanol

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Reaction Conditions

Reaction Steps

2-[(1R)-1-(3,4,5,6-Tetrahydro-2H-pyran-2-yl)oxyethyl]-2-(2,4-difluorophenyl)oxirane (82 g; manufactured by a method disclosed in Japanese Laid Open Application Hei 04/074168-A) and 6.3 g of pyridinium p-toluenesulfonate were dissolved in 600 ml of ethanol and the solution was stirred at 55° C. for 1 hour. The reaction solution was concentrated under reduced pressure. The residue was dissolved in 1 liter of ethyl acetate and the resulting solution was washed with water (2×200 ml). The aqueous layer was extracted with ethyl acetate (2×100 ml). The organic layers were combined, washed with saturated aqueous solution of sodium chloride, dried over magnesium sulfate and distilled off under reduced pressure. The residue was purified by silica gel chromatography (eluate ; hexane:ethyl acetate=10:1 to 8:1 to 3:1) to give 31.5 g of (1R)-1-[2-(2,4-difluorophenyl)-2-oxiranyl]ethanol as a pale yellow oil.

Provenance & Evidence