Oligosaccharides 1,6-anhydro, preparation

As a further illustration of the scope for use of 1,6-anhydro sugars in the preparation of uncommon sugars, the rare L-idose derivative 210 has been prepared recently and used in the preparation of oligosaccharides containing iduronic acid... 

Ether-linked oligosaccharides have been prepared from 5,6-anhydro-D-glucose derivatives,345 and 5,6-anhydro sugars have also afforded various polysaccharides.338,346... 

This reaction was then successfully applied in different modifications (—10% aqueous potassium hydroxide is mostly used), especially on the phenyl glycosides of aldohexopyranoses28 43 and of the corresponding oligosaccharides (see Sect. X,l,a), and still remains one of the methods frequently used for the preparation of l,6-anhydro-/3-D-glucopyranose31 38,40 (6) (for example, specifically labelled with carbon-14 see Ref. 44) and of l,6-anhydro-)3-D-galactopyranose.30,37 41,45 45a... 

The 2-acetamido derivative of DNJ (35) has been prepared by reaction of azide followed by reduction and acetylation of the corresponding 2,3-anhydro-o-mannose derivative. Compound 35 was incorporated into oligosaccharide mimics of sialyl Le and sialyl Le, ... 

Alginates-related oligosaccharides containing L-guluronic acids have been synthesized starting from L-ascorbic acid with the formation of protected 1,6-anhydro-p-L-gulopyranoses key intermediates. Di-, tri- and tetramers were prepared in excellent a-selectivily. ... 

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