Glycosyl compounds

Compounds in which the anomeric hydroxy group has been substituted by halogen atoms, pseudohalogen or amino groups are named quasi radico-functionally as glycosyl derivatives of the respective functional classes. 

6-Tri-O-methyl-a-D-arabmo-hexo-pyranosyl-2-ulose thiocyanate 

Methyl-(2,3-4-tri-0-acetyl-a-D-gluco-pyranosyl)uronate isocyanate systematically more logical would be Methyl-(2,3,4-tri-0-acetyl-l-isocyanato-1-deoxy-a-D-glucopyranuronate 

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C-Glycosyl compounds have a carbon atom ia place of the exocycHc oxygen atom of the acetal group and, therefore, are branched cycHc ethers. An example is the naturally occurring anthroquiaone dye, carminic acid [1260-17-9] (Cl Natural Red 4). 

Bivalent and tervalent residues 2-Carb-32. Radicals, cations and anions 2-Carb-33. Glycosides and glycosyl compounds... 

Fischer projection of acyclic form, 56-57 glycosides, 132-135 C-glycosyl compounds, 139-140 N-glycosyl derivatives, 137-139 glycosyl halides, 136-137 glycosyl residues, 125 isotopic substitution and isotopic labelling, 91 me so forms, 59 optical rotation, 59 parent structure choice, 53... 

The anion of nitromethane adds easily to the carbonyl functions of sugars. This is a useful strategy for extension of the carbon chain.100 2-Acetamido-2-deoxy-P-D-glucose (A-acetyl-D-glucosamine) is the carbohydrate unit of glycoproteins that occurs most often. The nitromethy-lation method provides a straightforward route to a series of C-glycosyl compounds with the acetamido functionality (Eq. 3.62).101... 

A few years later, the same group extended this strategy in order to access metabolically stable C-glycosyl clusters containing long-arm spacers via a sequence of transition metal-catalyzed transformations (Scheme 11).93 In this context, crossmetathesis reactions of various C-glycosyl compounds with alkenes having available... 

These model reactions were of great value in the extension of the C-glycosylation reaction with malonic esters to five-membered ring-systems. Treatment of 2,3 5,6-di-O-isopropylidene-a-D-manno-furanosyl bromide122,123 (150) with diethyl sodiomalonate led to an anomeric mixture of C-glycosyl compounds that could be separated by column chromatography, with the a (151) and /B (152) anomers in... 

The formation of the desired C-glycosyl compounds was found to be much more favored when nonparticipating groups were present in the starting halide. Thus, treatment of 2,3,5-tri-0-benzyl-/3-D-ribofuranosyl chloride124 (158) with diethyl sodiomalonate gave a mixture of the expected C-glycosyl compounds that were isolated as the benzoates (161 and 162) in 44 and 46% yields, respectively. The... 

Ohrui and Fox128 reported that treatment of 2,3-O-isopropylidene-5-O-trityl-jS-D-ribofuranosyl chloride (171) with diethyl sodiomalonate in 1,2-dimethoxyethane gave an anomeric mixture of C-glycosyl compounds (172) which, when allowed to equilibrate in ethanol containing sodium ethoxide, gave the )3 anomer (173) as the preponderant product. Similar observations were made with the C-... 

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