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I. Reactions of omega-linked disaccharides. II. Synthesis of the 2,4-di-O-methylSlessor, Keith Norman January 1964 (has links)
I. Reactions of ∝-Linked Disaccharides
Through reaction of specifically substituted maltoses, ∝-glucosidic disaccharide derivatives have been prepared.
Catalytic oxidation of benzyl β-maltoside yielded maltobiouronic acid. Tritylation of 1,6-anhydro-β-maltose made possible the preparation of the 6'-0-tosyl ester. Replacement of the tosylate with azide ion followed by reduction and hydrolysis yielded a small amount of 6'-amino-6' deoxy-maltose. Replacement of the tosylate with thiolacetate allowed the preparation
of 6'-deoxy-6’-mercapto-maltose. Iodide replacement
of the sulphonyl ester followed by reduction gave the 6’-deoxy-1, 6-anhydro derivative which was converted to 6’-deoxy-maltose by acetolysis and deacetylation.
A route for the preparation of 4-0-(∝-D-glucopy-ranosyluronic acid)-D-xylose by selective decarboxylation
of maltosyldiuronic acid was attempted and found unfeasible. Attempts to prepare 6-substituted maltoses by reaction of benzyl 4',6'-0-benzylidene-β-maltoside with various reagents were unsuccessful.
II. Synthesis of the 2,4-Di-0-methyl Tetroses
The four isomeric 2,4-di-0-methyl tetroses were prepared
by periodate oxidation of known methylated sugars. 2,4-Di-0-methyl-D-and L-erythroses were prepared from 4,6-di-0-methyl-D-glucose and 3,5-di-0-methyl-L-arabinose respectively. 2,4-Di-0-methyl-D-and L-threoses were prepared from 3,5-di-0-methyl-D-xylose and 1,4,6-tri-0-methyl-L-sorbose.
The tetroses were characterized as their crystalline 2,4-dinitrophenylhydrazones. The Rf and RG values of the free sugars were recorded in a variety of solvents including a silica gel thin-layer chromatography system. / Science, Faculty of / Chemistry, Department of / Graduate
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