D-Glucoascorbic Acid

Title: D-Glucoascorbic Acid
CAS Registry Number: 528-88-1
CAS Name: D-arabino-Hept-2-enonic acid g-lactone
Additional Names: 3-keto-D-glucoheptonofuranolactone
Molecular Formula: C7H10O7
Molecular Weight: 206.15
Percent Composition: C 40.78%, H 4.89%, O 54.33%
Literature References: A physiologically inactive homolog of ascorbic acid. Prepn: Ault et al., J. Chem. Soc. 1933, 741; Baird et al., ibid. 1934, 62; Reichstein et al., Helv. Chim. Acta 17, 510 (1934); Stacey, Turton, J. Chem. Soc. 1946, 661; Stedehouder, Rec. Trav. Chim. 71, 831 (1952). Review on analogs of ascorbic acid: Smith, Adv. Carbohydr. Chem. 2, 79 (1946).
Derivative Type: Monohydrate
Properties: Clusters of rod-like crystals with pointed ends from acetone + methanol + petr ether, mp 101-105° (Reichstein); mp 138° (Baird). Becomes anhydr at 70° under high vacuum, mp 191° (Ault). [a]D20 -14° (c = 1 as hydrate); [a]D20 -22° (c = 1 as hydrate in methanol); [a]D14.5 -37.8° (c = 2.41 in 0.01N HCl); [a]D20 -80° (c = 0.75 neutralized with NaOH). pK1 4.26; pK2 11.58. Soluble in water; moderately sol in alcohol.
Melting point: mp 101-105° (Reichstein); mp 138° (Baird); mp 191° (Ault)
pKa: pK1 4.26; pK2 11.58
Optical Rotation: [a]D20 -14° (c = 1 as hydrate); [a]D20 -22° (c = 1 as hydrate in methanol); [a]D14.5 -37.8° (c = 2.41 in 0.01N HCl); [a]D20 -80° (c = 0.75 neutralized with NaOH)
D-Glucuronic Acid D-Glucuronolactone D-Gulonic Acid D-Gulose Dhurrin