Calcium D-gluconate Research Articles

Degradation of calcium d-gluconate- 2-d with alkaline hydrogen peroxide

Degradation of calcium d-gluconate- 2-d with alkaline hydrogen peroxide

Preparation of some bromodeoxyaldonic acids

Reaction of L-ascorbic acid with hydrogen bromide in acetic acid gave 6-bromo-6-deoxy- L-ascorbic acid, which was converted into 5,6-dideoxy- D- glycero-hex-2,3-enono-1,4-lactone. Hexonic acids or their lactones also gave bromo compounds on treatment with HBrAcOH. From D-galactono-1,4-lactone a 6-bromo derivative was obtained. Calcium D-gluconate yielded 2,6-dibromo-2,6-dideoxy- D-mannono-1,4-lactone, whereas D-mannono-1,4-lactone gave 2,6-dibromo-2,6-dideoxy- D-glucono-1,4-lactone.

Oxidative decarboxylation of aldonolactones by cerium(IV) sulphate in aqueous sulphuric acid; synthesis of D-arabinose

Oxidations of D-glucono-1,5-lactone, D-glucono-1,4-lactone, calcium D-gluconate, and 3-deoxy-D-arabino-hexono-1,4-lactone by cerium(IV) sulphate in sulphuric acid were studied at 25 and at 37 °C, with various concentrations of reactants and acidities. The results indicated that it is the aldonic acid that undergoes oxidation; the stoicheiometry requires two cerium(IV) ions for the oxidation of one molecule of aldonic acid to the next lower sugar. The rate of disappearance of cerium(IV) ions depended directly on its concentration, but the dependence on the organic substrate concentration suggested the existence of an intermediate complex; this was proved by a spectrophotometric method. The complex undergoes slow unimolecular decomposition to a free radical, which reacts with CeIV to afford the products. The reaction rate was proportional to 1/[SO4H2]2. A preparative experiment with D-glucono-1,5-lactone gave crystalline D-arabinose in 94% yield.

D-Gluconic Acid: Isolation from the Defensive Secretion of the Cockroach Eurycotis decipiens

The major water-soluble constituent of the defensive secretion of Eurycotis decipiens was identified as gluconic acid, isolated in the form of calcium D-gluconate. The acid, in equilibrium with its lactones, is present in unusually high concentration.

Improvements in the Preparation of D-Arabinose from Calcium D-Gluconate and of D-Lyxose from Calcium D-Galactonate

Improvements in the Preparation of D-Arabinose from Calcium D-Gluconate and of D-Lyxose from Calcium D-Galactonate