an easy separation of some beta-ketoesters

beta ketoesters are quite acidic.
In some cases, shake the betaketoester with NaOH or KOH aqueous solution will make the Na or K salt of the betaketoester.
Depends on the structure of the ketoester, the salts may be soluable in water(K salt are more likely to be water-soluable than Na salt), so it can be extracted into water and then acidified by HCl to give the ketoester.
Na salt has less solubility in both water and organic solvent(ex. ether),so it will form a nice precipitation. an easy filtration can give you 99% Na salt of betaketoester, the drawback is the low yield of the precipitation.