Fischer-Leuchs synthesis

The Fischer-Leuchs synthesis of 2-amino-2-deoxy-D-gluconic acid9 (by hydrolysis of the corresponding nitrile, produced on addition of hydrogen... 

Some reference should be made in this review to Fischer and Leuchs synthesis of glucosamine from o-arabinose through the essential steps of the Fischer higher-carbon sugar process. However, the subject of the synthesis of amino sugars, which was later developed so extensively by P. A. Levene, has been reviewed in his monograph. 

The original intention of Leuchs and Fischer was to use NCAs in peptide synthesis, but the high reactivity of these reagents and their tendency to ohgomerize dampened the enthusiasm of most laboratories for these self-activated amino acids. Based on some successes in the early 1950s,workers at Merck developed conditions where controlled-sequence peptides could be synthesized in aqueous media.f l The crowning achievement involved the use of NCAs in the synthesis of ribonuclease A by the Merck group in 1969. 

Leuchs described the synthesis of several representative anhydrides of type 1 having different substituents. Although the discovery of Hermann Leuchs did not attract much attention at first, it has been expanded into one of the most important synthetic tools in protein research. Emil Fischer, whose institute in Berlin occupied a leading role in the research on sugars and proteins for 30 years, expressed at several occasions the opinion that his own synthetic polypeptides, and by extrapolation natural proteins, would be represented by long chains with the -CO-NH- unit as a recurring bond. 

Leuchs, Hermann (1879-1945), German chemist and discoverer of the N-carboxy anhydrides of amino acids. He carried out the work for his doctoral thesis under the direction of Emd Fischer on the synthesis of serine and glucosamine. In 1902, he received his D. Phd. degree and achieved independent status from 1904 onwards, Privatdozent (1910) and associate professor (1914). He turned down offers of frill professorships at the Universities of Graz and Braunschweig, which would have improved his position, in favor of a personal frill professorship at the Berlin Institute. He ended his life in the final days of World War II [F. Krohnke, Hermann Leuchs , Chem. Ber. 1952, 85, LV]. 

L-Serine isolated from a sulfuric acid hydrolyzate of sericine, a protein component of silk (lat. sericus silken) by E. Cramer. Structure by the same author. Synthesis E. Fischer and H. Leuchs, 1902. 

L-Hydroxyproline, formerly oxyproline isolated from acidic hydrolyzate of gelatin by E. Fischer. Structure by synthesis by H. Leuchs, 1905. Found only in collagen. 

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