C[Mg]I.[Mg].[CH3:5]I.[O:7]=[C:8]([CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])/[CH:9]=[CH:10]/[CH:11]1[CH2:13][C:12]1([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:14]([O:16][CH2:17][CH3:18])=[O:15].[NH4+].[Cl-]>CCOCC.O.C(OCC)(=O)C.C1C=CC=CC=1>[OH:7][C:8]([CH3:5])([CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])/[CH:9]=[CH:10]/[CH:11]1[CH2:13][C:12]1([C:14]([O:16][CH2:17][CH3:18])=[O:15])[C:19]([O:21][CH2:22][CH3:23])=[O:20]A solution of the lower alkyl magnesium halide, methyl magnesium iodide, prepared from 24.31 g of magnesium turnings and 157 g of methyl iodide in 1000 ml of ether, is cooled to -70°. Diethyl trans-2-(3-oxo-1-octenyl)cyclopropane-1,1-dicarboxylate (124.2 g); described in Example 3, in 600 ml ether is added slowly taking care that reaction mixture temperature does not exceed -45°. The mixture is stirred 75 min. at the temperature range -50° to -45°. Aqueous saturated NH4Cl solution is added slowly keeping the temperature of the reaction mixture below -55°. The mixture is diluted with water and extracted with 1500 ml ether. The ether layer is washed with saturated NaCl solution twice, then with 10% sodium thiosulfate solution twice, again with saturated NaCl solution, dried (NaSO4) and concentrated to give a greenish yellow oil. The oil is dissolved in ethyl acetate-benzene (3:17) and poured through a column of silica gel. The eluate is concentrated to yield the title compound, nmr (CDCl3) δ 0.88 (+, J = 5, 3H), 2.45 (q, 2H), 4.13 (q, 2H), 5.14 (2xd, J = 16.8, 1H), 5.72 (d, J = 16, 1H).
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