Thiosugars natural products

In the realm of thiosugars, the only pyranose known to be a natural product is 5-thio-D-mannose 7 (Figure 9.2), but more complex structures, salacinol 8 and cotalanol 9, have recently been found in plants known for their antidiabetic properties in Indian folk medicine. 

Thiosugars 4-Thioaldofuranoses 5-Thioaldopyranoses 5-Thioketofuranoses 6-Thioketopy-ranoses 6-Thioaldoseptanoses Thiosugar-related natural products Thiodisaccharides... 

Treatment of 3-(3 -methyl-2-oxobutyl>3-hydroxyindole with thionyl chloride gave, unexpectedly, the thiolan derivative (29), and reduction of tra f-4-phenyl-but-3-en-2-one with sulphurated sodium borohydride gave 3-acetyl-2,6-diphenyl-4-hydroxy-4-methylthian, of unknown configuration. The cis- and /runr-isomers of 2-mercaptothiolan-2,5-dicar-boxylic acid were formed by base-catalysed rearrangement of 1,2-dithian-3,6-dicarboxylic acid. Unexceptional methods were used to synthesize various thiosugar derivatives, and the synthesis of a-methylbiotin, a new natural product, by a modification of the Hofman-LaRoche method has been described. ... 

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