Cl[CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4].[OH-].[K+].[C:10]([CH:15]([CH2:21][C:22](=[O:24])[CH3:23])[C:16]([O:18][CH2:19][CH3:20])=[O:17])([O:12][CH2:13][CH3:14])=[O:11].[CH3:25]N(C)C=O>[Cl-].C([N+](CC)(CC)CC)C1C=CC=CC=1>[C:16]([C:15]([C:10]([O:12][CH2:13][CH3:14])=[O:11])([CH2:21][C:22](=[O:24])[CH3:23])[CH2:25][CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4])([O:18][CH2:19][CH3:20])=[O:17]4 ml (0.037 mol) of ethyl chloroacetate were added dropwise to a suspension of 2.1 g (0.037 mol) of finely powdered potassium hydroxide, 8 g (0.037 mol) of ethyl 2-carbethoxy-4-oxo-valerate, approx. 0.1 g of benzyltriethylammonium chloride and 150 ml of dimethylformamide. After about 15 hours' stirring at 20°-25° C., 2 ml (0.017 mol) of ethyl chloroacetate and 1 g (0.016 mol) of potassium hydroxide were again added to complete the reaction. The mixture was again stirred at 20°-25° C. for 2 hours, after which the reaction products were partitioned between ethyl acetate and 20 % strength by weight ammonium chloride solution. The organic phase was washed twice, each time with 50 ml of 20 % strength by weight ammonium chloride solution, then dried and evaporated down. Yield: 9.5 g of an oil containing 91% of the product. Purification was effected by fractional distillation (bp0,l mm HG : 135° C.).
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