4-Amino-l",6"-anhydro

The deamination of methyl 3-amino-3-deoxy-/3-D-altropyranoside was studied in 1934, but the products were not fully characterized.14411 The syrupy product was converted into a methylated derivative that had an elemental analysis corresponding to that calculated for a methyl tetramethylhexoside. The conditions used for methyl-ation would have opened an epoxide ring. Methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside precipitated quantitatively from solution when the corresponding 3-amino-3-deoxyaltroside derivative was deaminated in aqueous medium.145 Epoxide formation was likewise reported to be quantitative in the deamination of the analogous 2-amino-2-deoxyaltroside.83 145 On deamination, 4-amino-l,6-anhydro-4-deoxy-/3-D-mannopyranose also gave an epoxide, namely, 1,6 2,3-dianhydro-/3-D-talopyranose, in unspecified yield.146... 

M. Cerny, I. Cerny, and T. Trnka, Ammonolysis of l,6-anhydro-2,4-di-0-tosyl-/l-D-glucopyranose and l,6 3,4-dianhydro-2-0-tosyl-/l-D-galactopyranose preparation of 4-amino-l,6-anhydro-4-deoxy-/J-D-manno- and -/1-D-altropyranose, Carbohydr. Res., 67 (1978) 33-41. 

Amino-l,6-anhydro-3-deoxy-/3-D-galactopyranose456 and 4-amino-l,6-anhydro-4-deoxy-/Q-D-talopyranose439,457 have been prepared by the reduction of oximes. 

A rather complex reaction of the amino 1,6-anhydrohexopyranoses is their deamination with nitrous acid, which was studied for the 2-, 3-, and 4-amino derivatives of l,6-anhydro-/3-D-glucopyranose77 and for 4-amino-l,6-anhydro-4-deoxy-/3-D-mannopyranose.771 The formation of epoxides, besides other products, was observed in all instances (compare Ref. 698). On the other hand, according to previous findings,698 the deamination of the 2-amino 3,4-diacetate 159, having no free hydroxyl group, involves rearrangement of the C-1-0-6... 

The aziridine ring is more stable than the oxirane ring in alkaline solution, as demonstrated by the low reactivity in attempts to accomplish isomerization of the hydroxyepimines to amino epoxides in alkaline media at room temperature, which contrasts with the rapid epoxide migration (see Sect. V,2). Isomerization of hydroxyepimines occurs only at high temperatures, and leads finally to the formation of amino derivatives of 1,6-anhydrohexoses.379,740 For example, when 166 is heated in 5% potassium hydroxide, 2-amino-l,6-anhydro-2-deoxy-/3-D-mannopyranose (168) is formed as the main product this can be explained by transient formation of 2-amino-l,6 3,4-dianhydro-2-deoxy-/3-D-altropyranose (167), and its subsequent, diaxial hydrolysis.379 Compound 167 is probably in equilibrium with epimine 166. Acid hydrolysis of the aziridine ring in 153 also follows a diaxial mechanism, without scission of the 1,6-anhydride bond, to give 4-amino-l,6-anhydro-4-deoxy-)8-D-mannopyranose756 (177). 

M. Cerny, I. Cerny, and 1. Pacak, Syntheses with anhydro sugars 27. Preparation of 4-amino-l,6-anhydro-4-deoxy-p-D-glucopyranose— isomerization of 4-amino-1,6-2,3-dianhydro-4-de-oxy-p-D-mannopyranose to l,6-anhydro-3,4-dideoxy-3,4-epimino-p-D-altropyranose, Collect. Czech. Chem. Commun., 41 (1976) 2942-2951. 

Amino-l,6-anhydro-4-deoxytalose, A-145 l-Amino-2,5-anhydro-l-deoxyxylitol, A-146... 

Amino-l,6-anhydro-4-deoxytalose p-D- ranose-/< rm, A-145 2-Amino-2-deoxy-p-D-glucopyranosyl-(l 3)-[2-amino-2-deoxy-p-D-... 

Amino-2,7-anhydro-4-deoxy-a//o-heptulose p-D-Pyranose-ybrm, A-134 4-Amino-2,7-anhydro-4-deoxy-fl/ r(7-heptulose p-D-Pyranose-/orm, A-135 4-Amino-2,7-anhydro-4-deoxy-gw/o-heptulose p-D-Pyranose-/orm, A-136 4-Amino-l,6-anhydro-4-deoxy-p-D-inannopyranose, A-314 4-Ainino-l,6-anhydro-4-deoxytalose p-D- ranose-/orw, A-145 4-Amino-4-deoxyarabinose p-L-Pyranose-/orm 1-Dihydrogen phosphate,... 

An analogous bond migration was evident on deamination of 3,4-di-0-acetyl-2-amino-l,6-anhydro-2-deoxy-p-D-glucop3U anose with sodium nitrite in aqueous acetic acid, since l,3,4-tri-( -acetyl-2,6-anhydro-p-D-maraiopyranose was isolated following acetylation of the products. 

Die Desaminierung von Aminozuckern fiihrt in manchen Fallen zu ver-schiedenen Anhydro-Derivaten. Im Falle der 4-Amino-4-desoxy-l,6-anhydro-fl-D-mannopyranose wurde unter Waldenscher Umkehr am C-4 die l,6-3,4-Dianhydro-j3-D-talose erhalten is.nv). 

O-bcnzylideno-S-desoxy- -o-altrosido,1 a 6-araioo- B deBoxy 1,2 im propylidcno-ot-n-gluoofuranoBe,106 and 4-amino-l,0-anhydro-4-d esoxy-0-D-mannoee 05 to their respective ankydio derivatives on diazodnv tion (Eqs. 201-204). 

M. Chandler, M. J. Bamford, R. Conroy, B. Lamont, B. Patel, V. K. Patel, I. P. Steeples, R. Storer, N. G. Weir, M. Wright, and C. Williamson, Synthesis of the potent influenza neuraminidase inhibitor 4-guanidino Neu5Ac2en. X-ray molecular structure of 5-acetamido-4-amino-2,6-anhydro-3,4,5-trideoxy-D- rrt/fro-L-g/Mco-nonionic acid, J. Chem. Soc. Perkin Trans., 1 (1995) 1173-1180. 

Another route to 5-amino-5-deoxy-L-idose proceeds from 5-(benzyl-amino)-5-deoxy-l,2-0-isopropylidene-R-L-idurononitrile (56), which is readily obtainable from 1,2-O-isopropylidene-a-D-xj/lo-pentodialdo-1,4-furanose (13) by reaction with benzylamine and hydrogen cy-anide. Partial hydrogenation of the nitrile 56 by the Kuhn procedure, in acid solution, leads to the hexodialdose (57), which is reduced with sodium borohydride to 5-amino-5-deoxy-l,2-0-isopro-pylidene-jS-L-idofuranose. From this compound, tbe acyclic bisulfite adduct (58) is obtained by reaction with sulfiirous acid. Treatment of 58 with barium hydroxide gives crystalline 5-amino-l,6-anhydro-5-deoxy-jS-L-idopyranose (60) in almost quantitative yield. The equilibrium between the pyranose form (61) and its 1,6-anhydride (60) lies far on the side of Ae bicyclic form (60). The equilibrium can be evaluated from the optical rotation of the solution obtained by treat-... 

The course of ammonolysis of 111 is rather complicated, and the reaction results in a mixture containing 2,4-diamino-l,6-anhydro-2,4-dideoxy-j8-D-glucopyranose756 (154) (compare Ref. 513) and 1,6-an-hydro-3,4-dideoxy-3,4-epimino-/3-D-altropyranose756 (153) as the major products. This reaction course may be most satisfactorily explained by the sequence 111—>151 152, where 4-amino-1,6 2,3-dianhydro-4-deoxy-/3-D-mannopyranose (152) partly isomerizes (see Sect. VI,2) to the epimine 153, and partly reacts with ammonia to give740 the diamino derivative 154. 

This compound was mistaken for4-amino-l,6-anhydro-4-deoxy-/8-D-glucopyranose. 

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