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

HRID 625706

Reaktionsgleichung

[CH2:1]([O:3][C:4]([C@@H:6]1[CH2:8][C@H:7]1[C:9]1[CH:14]=[CH:13][C:12]([O:15]C)=[CH:11][CH:10]=1)=[O:5])[CH3:2].B(Br)(Br)Br.C(O)C>ClCCl.C(=O)(O)[O-].[Na+]>[CH2:1]([O:3][C:4]([C@@H:6]1[CH2:8][C@H:7]1[C:9]1[CH:10]=[CH:11][C:12]([OH:15])=[CH:13][CH:14]=1)=[O:5])[CH3:2]

Komponenten

Reaktionsbedingungen

Temperatur: -78 °C

Versuchsvorschrift

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]+.

Aufarbeitung

temperatureto warm to −20° C.
temperaturethe mixture warmed to room temperature
customThe phases are separated
extractionthe aqueous phase extracted with dichloromethane
customThe combined organic phases are dried through a phase separator
customthe solvent removed under vacuum
customThe residue is purified by flash chromatography (10% ethyl acetate in cyclohexane)
customcrystallized from 10% ethyl acetate in cyclohexane

Quellen und Nachweise

ORD-Eintrag: ord-4f6af052fac2458eacd2d86195962001
Quelldatensatz: uspto-grants-2016_04
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US09308194B2

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