[CH3:1][Mg]Br.C(O[C:7]([C:9]1([CH2:16][CH2:17][O:18][CH3:19])[CH2:14][CH2:13][C:12](=[O:15])[CH2:11][CH2:10]1)=[O:8])C.[NH4+].[Cl-]>C1COCC1>[CH3:19][O:18][CH2:17][CH2:16][C:9]12[CH2:10][CH2:11][C:12]([CH3:1])([CH2:13][CH2:14]1)[O:15][C:7]2=[O:8]Methylmagnesium bromide (3.0M in diethyl ether, 1.22 mL) was dissolved in THF (5 mL). The mixture was cooled to 0° C. and a solution of 1-(2-methoxy-ethyl)-4-oxo-cyclohexanecarboxylic acid ethyl ester (350 mg, obtained in example 1, step 2) in THF (5 mL) was added dropwise over a period of 5 minutes. The resulting mixture was stirred at 0° C. for 3 hours. The reaction mixture was poured into ice/water and acidified with sat. NH4Cl. The aqueous phase was extracted two times with ethyl acetate and the organic layers were washed with brine, dried over Na2SO4, filtered and the solvent was evaporated. The residue was purified by flash chromatography (silica gel, gradient of heptane in ethyl acetate) to give the title compound as a colorless liquid (67 mg, 22%). 1H-NMR (8, CDCl3): 3.55 (t, 2H); 3.31 (s, 3H); 1.86 (t, 2H); 1.84-1.73 (m, 8H); 1.39 (s, 3H).
Wird geladen…
