反应详情

100 parts of bottom product (7) from the first column (1) are passed into the second column (2) with 40 theoretical plates. 0.1 l of xylene (isomer mixture) is added as water entrainer and is returned (10) via line 8 and a phase separator (3) continuously into the column. With a distillate temperature of 28° C., a distillate pressure of 70 mbar and a reflux ratio of 1.6, 23 parts of overhead product (9) of the composition 80.1% by weight of water, 11.2% by weight of acetic acid, 3.3% by weight of methanol, 1.8% by weight of ester of tetrahydropyran-4-carboxylic acid and 44 parts of bottom product (12) with the composition 0.1% by weight of ester of tetrahydropyran-4-carboxylic acid, 10.7% by weight of 3-spirocyclopropylbutyrolactone, 28.9% by weight of 3-(2-methoxyethyl)butyrolactone, 6.1% by weight of 3-(2-hydroxyethyl)butyrolactone and 15.1% by weight of 3-(2-acetoxyethyl)butyrolactone are obtained. At 108° C., 33 parts of side stream (11) with the composition 99.5% by weight of ester of tetrahydropyran-4-carboxylic acid are removed at plate 27.