Glucopyranosyl 2-acetamido-tetra-0-acetyl-2-deoxy

The disaccharide derivative 0-(2,3,4,6-tetra-0-acetyl-/ -D-galactopy-ranosyl)-(l— 3)-0-(2-acetamido-6-0-benzoyl-2-deoxy-/ -D-glucopyran-osyl)-(l— 3)-N-(benzyloxycarbonyl)-L-serine methylamide (192) was prepared by condensation of 3-0-(2-acetamido-2-deoxy-6-0-benzoyl-/ -D-glucopyranosyl)-N-(benzyloxycarbonyl)-L-serine methylamide (191) with tetra-O-acetyl-a-D-galactopyranosyl bromide147 (110) under the conditions of the Helferich-Wedemeyer procedure. Treatment of 192 with methylamine in methanol at 0° gave89 193. 

Interestingly, l,3,4,6-tetra-0-acetyl-2-amino-2-deoxy-a-D-glucopyranose hydrobromide (4) reacts with silver thiocyanate31 to give 2-acetamido-3,4,6-tri-0-acetyl-2-deoxy-/3-D-glucopyranosyl isothiocyanate (5), in a reaction which must involve an 0- N acetyl migration. 

The radical formed by detachment from the anomeric hydroxyl group is indicated by replacing the final letter e by yl as in bromide 4.21 or dipotassium phosphate 4.22 of tetra-O-acetyl-a-D-glucopyranosyl. In the case of a replacement by an amino group, the suffix amine is added, as in 2-acetamido-2-deoxy-j3-D-glucopyranosylamine 4.23. 

Subsequently, Jeanloz and Flowers reported the synthesis of methyl hyalobiuronic acid (II.3) by condensation of l-bromo-2,3,4,6-tetra-0-acetyl-a-D-glucopy-ranoside (II.4) with II.5 in the presence of mercuric cyanide [Hg(CN)2], followed by deacetylation to produce II.6 (Scheme 5). Removal of the 4,6-O-benzylidene with acid afforded II.7, methyl 2-acetamido-2-deoxy-3-0- (j8-D-glucopyranosyl)-a-D-glu-copyranoside, in 35% yield. Attempts to selectively oxidize C6 of the D-glucose moiety in II.7 to the corresponding carboxylic acid with platinum oxide proved unsuccessful. 

The preparation, X-ray crystal structure and ab initio calculation of the charge distribution of lV-(2-acetamido-3,4,6-tri-0-acetyl-2-deoxy-p-D-glucopyranosyl)-pyridinium chloride have been reported. The anomeric iV-(2,3,4,6-tetra-0-acetyl-D-glucopyranosyl)-4-dodecylpyridinium bromides were prepared as novel cationic surfactants. The panel of five substituted-pyridinium salts 15 were synthesized from the peracetylated glycosyl chloride of p-D-lV-acetyl-neuraminic acid and used to probe the mechanisms of enzymatic and non-enzymatic hydrolysis of neuraminides. " Detailed analysis of the solvolysis of Af-(2-deoxy-a- and p-D-glucopyranosyl)-4-bromoisoquinolinium tetra-fluoroborate in aqueous alcoholic solvents indicated Sjv2-like transition states. 

Yi,3,4,6-Tetra-Ac 2-Acetamido-3,4,6-tri-O-acetyl-2-deoxy-P-D-glucopyranosyl azide... 

There have been reports of various 3-cyano-l-p-D-glucopyranosyl- and -1-P-D-galactopyranosyl-pyridin-2-ones and pyridin-2-thiones, along with o-l-arabinopyranosyl- and P-D-xylopyranosyl-3-cyano-2-pyridinethiones. 5-Amino-6-aryl-3-(P-D-gluco-or -galacto-pyranosyl)tetrahydro-2-thioxo-4H-1,3-thiazin-4-ones have been made by elaboration of the appropriate tetra-O-acetyl-P-D-hexopyranosyliso thiocyanates, and l-(2-acetamido-2-deoxy-P-D-glucopyra-... 

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