Analogues of Trisaccharides and Compounds with Anomalous Linking

5 Analogues of Trisaccharides and Compounds with Anomalous Linking - In 

The chitinase inhibitor allosamidine is a trisaccharide analogue with two N-acetylallosamine units bonded to a highly functionalized cyclopentano-oxazoline unit - allosamizoline. Analogues have now been described with one JV-acetylallo-samine unit, with the disaccharide bonded to an alternative hydroxyl of the cyclopentane, and thirdly with the oxazoline ring inverted.  

Two recently synthesized oligosaccharide-containing forms of calicheomycin Yi bind strongly to certain duplex DNA sequences. Danishefsky has published a long paper on the details of his total synthesis of this compound and of dynemicin A, including the carbohydrate components.  

Analogue 10 of neamine with 5-amino-5-deoxy-p-D-ribofuranose attached by a flexible linker has been made as a potential inhibitor of HIV,and the epimeric GMl mimetics 11 have been described. Rearrangement of the triunsaturated maltotriose derivative 12, made from the 6,6, 6 -trideoxy-triiodo-maltotrioside derivative, by treatment with tri-isobutylaluminium, followed by DMSO, acetic anhydride oxidation of the triol formed, gives the tricarba-trisaccharide tricarbonyl derivative 13 in 33% yield. This, importantly, adapts the known conversion of 6-deoxyhex-5-enosyl compounds into deoxyinososes in such a way that the glycosidic bonds are preserved. 

In the area of nitrogen-in-the-ring sugar analogues compound 14 has been made as a SiaLe mimetic.  

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