Sodium Tartrate → Calcium tartrate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To the culture broth obtained in Example 1, 1.0 g of disodium cis-epoxysuccinate was added. The culture broth was adjusted to pH 8.0 and shaken at 35° C for four hours. The newly added substrate was used up and the culture broth was found to contain 1.29 g of sodium L(+)-tartrate (59 percent of yield of sodium L(+)-tartrate based on the whole substrate charged, 78 percent of yield of sodium L(+)-tartrate based on the newly incorporated substrate). In this manner, 1.0 g portions of disodium cis-epoxysuccinate were added one after another to a total of 20.0 g. Finally, the substrate thus successively added was wholly used up and the culture broth was found to contain 2.18 g of sodium L(+)-tartrate (89 percent of yield of sodium L(+)-tartrate based on the whole substrate charged). The culture broth was centrifuged to afford a supernatant. By adding to the supernatant about 120 ml of a calcium chloride solution having a concentration of 1 mol/l, there was obtained the precipitate of calcium L(+ )-tartrate. The precipitate was separated by filtration and suspended in about 200 ml of water. While the suspension was kept under agitation, 1N sulfuric acid was added until the pH value of the suspension became 1.8. The precipitate of calcium sulfate thus produced was separated by filtration. The filtrate was concentrated to dryness under reduced pressure to afford 14.7 g of L(+)-tartaric acid in the form of crystals. The crude crystals thus obtained were dissolved in water. The aqueous solution was passed through a column measuring 3 × 80 cm and packed with Amberlite IR 120 (H+ type cation-exchange resin) and the adsorbate was eluted with about 1000 ml of water. The resultant eluate was passed through another column measuring 3 × 80 cm and packed with Amberlite IRA 400 (formic acid type anion-exchange resin) and the adsorbate was eluted with about 1000 ml of 9N formic acid. The eluate thus obtained was concentrated to dryness under reduced pressure to afford 13.5 g of pure tartaric acid. The L(+)-tartaric acid thus produced was found to have an optical purity of 100 percent.

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