C([O:4][C:5]([C:7]1([CH2:13][CH:14]([CH2:17][CH3:18])[CH2:15][CH3:16])[CH2:12][CH2:11][CH2:10][CH2:9][CH2:8]1)=[O:6])CC.CC([O-])(C)C.[K+].O.OS(O)(=O)=O>C1COCC1>[CH2:17]([CH:14]([CH2:15][CH3:16])[CH2:13][C:7]1([C:5]([OH:6])=[O:4])[CH2:8][CH2:9][CH2:10][CH2:11][CH2:12]1)[CH3:18]1-(2-Ethyl-butyl)-cyclohexanecarboxylic acid n-propyl ester (2.3 g, 9.04 mmol) was added dropwise under stirring to a solution of KOtBu (4.058 g, 36.2 mmol) in THF (17 mL) containing a small amount of water (244 mg, 13.6 mmol). The mixture was stirred 20 h at 54° C., cooled to room temperature, slowly poured onto a mixture of ice and 4N H2SO4 and extracted with DCM (2×150 mL) after adjusting to pH 1. The organic phases were washed with diluted aq. NaCl (100 mL), combined, dried over sodium sulfate and concentrated to afford 1.901 g (99%) 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid, purity 96% (GC area).
読み込み中…
