[OH:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([O:9][CH2:10][CH3:11])=[O:8].CN(C)C1C=CC=CC=1.Cl[C:22]([O:24][CH2:25][CH3:26])=[O:23]>C1(C)C=CC=CC=1>[CH2:25]([O:24][C:22]([O:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([O:9][CH2:10][CH3:11])=[O:8])=[O:23])[CH3:26]160 g of ethyl 6-hydroxy-hexanoate, 145.4 g of N,N-dimethylaniline and 200 ml of anhydrous toluene are placed in a round flask which is provided with a dropping funnel, a thermometer and a stirrer. 119.4 g of ethyl chloroformate are added dropwise at 25° C. within a half hour while stirring. The reaction mixture is held under reflux for 3 hours. After cooling the reaction mixture is poured on to ice-water, the organic phase is washed twice with water, with 100 ml of a 5% hydrochloric acid solution and then neutral with water. After drying over sodium sulphate the solvent is distilled off. 173 g of crude product are obtained. Fractional distillation gives 112 g (yield 48.3% of theory) of chemically pure ethyl 6-ethoxycarbonyloxy-hexanoate; 75 g thereof can be used as an olfactorily pure product without further treatment.
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