Cardiac glycosides synthesis

Pyran-4-one, 2,2,5-trimethyl-2,3-dihydro-photodimerization, 3, 720 4H-Pyran-4-one, 2,3-dihydro-2,3,5-trimethyl-6-( 1 -methyl-2-oxobutyl)-synthesis, 3, 844 Pyranones alkylation, 2, 56 aromaticity, 3, 632, 633 C NMR, 3, 587, 635 H NMR, 3, 580 cardiac glycosides, 3, 883 chromone synthesis from, 3, 830 colour couplers... 

This process starts with the synthesis of novel chemical compounds. Substances with complex structures may be obtained from various sources, e.g., plants (cardiac glycosides), animal tissues (heparin), microbial cultures (penicillin G), or human cells (urokinase), or by means of gene technology (human insu-Un). As more insight is gained into structure-activity relationships, the search for new agents becomes more clearly focused. 

Synthesis of 2-Desoxyhexomethyloses Which Occur in Cardiac, Glycosides 89... 

In recent years the chemistry of 2-desoxysugars generally, has been considerably broadened. In particular, new methods of synthesis have been developed for the preparation of many of the didesoxysugars known as the 2-desoxyhexomethyloses which occur naturally as components of the cardiac glycosides. The formation, structure, and stability of various 0- and iV-glycosides of sugars of this class have been examined in... 

Oxidation with Potassium Permanganate.—Oxidation with potassium permanganate of 2- and 3-desoxyhexose monomethyl ethers, obtained from the cardiac glycosides or by synthesis, has been employed extensively by Reichstein and his colleagues, since valuable information on the structures of the sugars is thereby provided. This reaction results in the formation from either a 2-desoxyhexose 3-methyl ether or a 3-desoxyhexose 2-methyl ether, of one of the isomers of methoxysuccinic acid, which is usually isolated as the diamide. 

This expeditious route to spectinomycin not only compares favorably with two previous syntheses of this antibiotic, one elaborating the pyranoid half from D-glucose in over 20 steps (44), the other requiring nine from the rather incommodiously accessible L-glucose (45), in addition, this approach is versatile enough to lend itself to the synthesis of uscharidine type cardiac glycosides from steroidal diols. 

Yasuhiro TH, Mitsuo N, Satoh T. Enzymic synthesis of chemically unstable cardiac glycosides by 3-galactosidase from Aspergillus oryzae. Tetrahedron Lett. 1984 25 2241-2244... 

J. Thiem and S. Kopper, Synthesis of cardiac glycosides evatromonoside and its anomer, Angew. Chem. Int. Ed. Engl., 21 (1982) 779-780. 

Carbohydrates (Interscience, New York, 1960) p 104. Synthesis Bollinger, Ulrich, Helv. Ckim Acta 35, 93 (1952). Review R. C. Elderfjeld, The Carbohydrate Components of Cardiac Glycosides in W. W. Pigman, M. L-. Wolfrom, Advances in Carbohydrate Chemistry vol. I (Academic Press, New York. 1945) pp 147-173. 

---