Die Synthese der d‐Ascorbinsäure (d‐Form des C‐Vitamins)

Abstract

hiichst pereinigten Vitamin-A-praparate anbelangt, so besteht aber imnier noch die Miiglichkeit, dass sie neben dem Hauptprodukt kleine JIengen von Isomeren enthdten.Eine ausfiihrlichere Beschreibnnp der vorerwahnten Untersuch ungen sol1 clemniichs t erfolgen.Ziirich, Chemisches Institnt der Universitgt .Die Synthese der d-Ascorbinsaure (d-Form des C-Vitamins)' (Vorlaufige Mitteilung) von T. Reiehstein, A. Grtlssner und R. Oppenauer. (5. IV. 33.) Seit der Entdecknnp von Szent-Gyiirgyi, dsss der von ihm fruher iius tierischem und pflenzlichem Material isolierten ,,Hexuronsiiure"l) antiscorbutische Wirksamkeit zukommt,), ist diese Substanz an verschiedenen Stellen eifrip erforscht worden. Es hat dies zur Aufstellung der foIgenden 3 Strukt~rforrneln~) gefiihrt : Y Y CH+2H-C0-CH2-CO-CO0H CHI-CH-CH,-CO-CO-COOH I1 5 ) OH OH I) Biochem. J. 22, 1387 (1928). %) Nature 130, 576 (1932). 3, Vgl. ferner die inzwischen erschienene Arbeit von Hirst, J. Soc:Chem. Ind.

Synthesis of L-Ascorbic Acid

“…In early 1933, Micheel and Kraft (8) suggested that carboxylic acid (6) was the structure for L-ascorbic acid. A short time later the synthesis of D-ascorbic acid shown in Scheme 4 starting with D-xylosone was reported (9)(10)(11)(12). This synthe sis gave material identical with natural L-ascorbic acid, except for the specific rotation, and was used (9-12) as evidence to support structure 6…”

History of Industrial Biotechnology

“…This was replaced by the seven -step Reichstein synthesis in 1933 [97] , which included a biosynthetic step. After chemical conversion of D -glucose to D -sorbitol, Gluconobacter oxydans was used to convert the latter to L -sorbose.…”

Amino Acids, Lactic Acid and Ascorbic Acid as Raw Materials for Biocompatible Surfactants

“…The synthetically produced l-AA is used for different applications in the pharmaceutical, food, beverage and feed industries [14]. Originally isolated from lemons, the first chemical l-AA synthesis process from l -xylosone was achieved in 1933 [15,16]. During the past 70 years, the Reichstein process (from d -glucose) has gained all the advantages that would be expected after such a long period of application and development [16].…”

“…Originally isolated from lemons, the first chemical l-AA synthesis process from l -xylosone was achieved in 1933 [15,16]. During the past 70 years, the Reichstein process (from d -glucose) has gained all the advantages that would be expected after such a long period of application and development [16]. Nevertheless, the process is still mostly energy consuming; high temperatures and pressures are necessary for some steps of the process.…”

“…Alcanoyl-6-O-ascorbic acid esters with different chain lengths (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) shorter homologue, octanoyl-6-O-ascorbic acid forms nearly spherical micelles in water solution above a CMC of about 6 mM at 30 • C while decanoyl and dodecyl derivatives are poorly soluble in water. Ascorbyl palmitate and its alkali salts are amphiphilic molecules practically insoluble in water at room temperature, but their solubility increases rapidly with temperature.…”