2- Azido-2-deoxy derivative

P. L. Garegg and M. Haraldsson, Studies on C-5 epimerization of 2-amino-2-deoxy and 2-azido-2-deoxy derivatives of allyl /1-D-galactopyranosiduronic acid esters, Tetrahedron, 46 (1990) 13-17. 

The 2-azido-2-deoxy derivatives of mono- and disaccharides such as 27a and 27b are versatile intermediates in the preparation of 2-amino-2-deoxysaccharides23. 

Methyl 6-amino-6-deoxy-a-D-glucopyranoside derivatives 2c were synthesized in our laboratory by a somewhat different procedure [31]. 6-0-Sulfonyl or 6-bromo-6-deoxy derivatives of methyl a-o-glucopyranoside were substituted at C-6 by sodium azide. The 6-azido-6-deoxy intermediate was then treated by acyl chlorides in the presence of triphenylphosphine (Staudinger reaction) to afford amido derivatives which were finally de-O-acetylated to give 2c. The same reaction pathway allowed the preparation of 6-alkylamido-6-deoxy-D-glucopy-ranose derivatives, starting from o-glucose [31]. 

The synthesis of a 9-azido-9-deoxy derivative of Neu5Ac, namely, 5-acetamido-9-azido-3,5,9-trideoxy-D-gh/cero-D-ga/acto -2-nomdo-pyranosonic acid, from enolpyruvate phosphate and 2-acetamido-6-azido-2,6-dideoxy-D-mannose, using Neu5Ac synthase from A. meningitidis, has been reported.225... 

M. Kloostennan, M. P. de Nijs, and I. H. van Boom, Synthesis of 1,6-anhydro-2-0-trifluoro-methanesulphonyl-B-D-mannopyranose derivatives and their conversion into the corresponding 1,6-anhydro-2-azido-deoxy-p-D-giucopyranoses A convenient and efficient approach, J. Car-bohydr. Qum. 5 215 (1986). 

M. Bols, I. Lundt, and E. R. Ottosen, Preparation of 2-, 3-, and 4-deoxy derivatives of L-rhamnose, and derivatives of 2-azido-2-deoxy-L-rhamnose and 2,6-dideoxy-2-fluoro-L-glucose, for use in glycosylation reactions, Carbohydr. Res., 222 (1991) 141-149. 

Cellulose can be oxidized to different degrees of C6-aldehyde content by photolysis of the 6-azido-6-deoxy derivatives [51]. The / -elimination reaction of the 6-aldehyde (Scheme 2) may lead to terminal double bonds exhibiting a UV absorption Umax = 250 nm) [52,53]. With model C6-aldehyde celluloses, /3-elimination started at 30 °C at pH 9 at elevated temperatures (80 °C) -elimination was detected already at very low pH levels (pH 3.5). Similar results were obtained with HOCl-oxidized pulps, with -elimination starting at room temperature at pH 8.5 (unpublished results). 

Oxidation products from starch are also available indirectly. For example, Horton and coworkers485-487 prepared 6-aldehydo amylose and starch derivatives by photolysis of 6-azido-6-deoxy derivatives. The oxidation pattern of starches can be determined by hydrolysis of the reaction product and subsequent identification of the components of such hydrolyzates as their trimethylsilyl derivatives 488... 

From study of the action of invertase on derivatives of sucrose and methyl jS-D-fructofuranoside, it was concluded that small changes at positions 1, or 6 cause loss of enzymic acitivity various azido-, deoxy, and halogenated-derivatives were examined. " ... 

Per-6-bromo-6-deoxy derivatives of a-, P- and ycyclodextrin have been produced using triphenylphosphine and bromine in DMF, the yields being almost quantitative. Nucelophilic displacements then led to per-cyano-, azido-and sulfur-linked compounds in excellent yields. It has therefore become easy to... 

Azido-sugar derivatives such as 51 were synthesized conventionally from the known trichloroethylidene carbamate derivatives such as 52, prepared by a one-pot acetalation-epimerization procedure from methyl a-D-mannopyrano-side (see Section 2.1) The 2,6-anhydro-5-azido-2-C-hydroxymethyl-L-allohep-tose derivative 53 has been synthesized from a racemic norbornenone derivative. 6-Azido-6-deoxy-, and 5,6-diazido-, 5-azido-6-fluoro- and 6-azido-5-fluoro-5,6-dideoxy-D-fructoses 54 have been prepared by polyol dehydrogenase-catalysed isomerization of the corresponding D-glucose derivatives. ... 

A number of purine 2 -amino-2 -deoxy-8-D-ribonuc1eosides have been prepared by microbial transglycosy1 ation between the purine base and 2 -amino-2 -deoxyuridine. The 3 -azido-3 -deoxy-6- and 3 -azido,2, 3 -dideoxy-a- and 3-D-ribofuranosides of benzimidazole were synthesized conventionally from 3-azido sugar derivatives. 

Brossmer, R. Rose, U. Kaspar, D. Smith, T. L. Grasmuk, H. Unger, F. M., Enzymic synthesis of 5-acetamido-9-azido-3,5,9-trideoxy-D-glycero-D-galacto-2-nonulosonic acid, a 9-azido-9-deoxy derivative of N-acetylneuraminic acid. Biochem Biophys Res Commun 1980, 96, (3), 1282-1289. 

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