Ethanol → (1R,2R)-ethyl 2-(4-hydroxyphenyl)cyclopropanecarboxylate

関与物質

反応条件

反応手順

2-(4-Methoxy-phenyl)-trans-cyclopropanecarboxylic acid ethyl ester (1.43 g, 6.51 mmol) is dissolved in dry dichloromethane (30 mL) and cooled to −78° C. Boron tribromide solution (1 M in dichloromethane, 7.81 mL, 7.81 mmol) is added dropwise then the mixture is allowed to warm to −20° C. and stirred overnight at −20° C. Ethanol (3 mL) is added and the mixture warmed to room temperature then diluted with saturated aqueous sodium bicarbonate solution. The phases are separated and the aqueous phase extracted with dichloromethane. The combined organic phases are dried through a phase separator and the solvent removed under vacuum. The residue is purified by flash chromatography (10% ethyl acetate in cyclohexane) and then crystallized from 10% ethyl acetate in cyclohexane to give the title compound (yield 0.58 g). LC (METHOD 11): tR=6.25 min; Mass spectrum (ESI+): m/z=248 [M+H+MeCN]+.

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