Methyl 4-azido-4-deoxy

In the arabinose series, methyl 4-azido-4-deoxy-/3-L-arabinopyrano-side (188) was transformed into the corresponding 4-acetamido compound the hydrolysis of this compound has not yet been investigated.A series of other 4-azido-4-deoxy-2,3-anhydroaldopento-pyranosides has been synthesized they should be valuable intermediates for the preparation of other 4-aminoaldopentoses. 

The only methyl 4-azido-4-deoxy-2,3-di-0-(methylsulfonyl)-D-pentopyranoside (obtained by selective azide displacement at C-4) containing a sulfonyloxy group not subject to the above factors was the /3-D-xylo isomer, and this could be further substituted by azide— presumably341 at C-3. 

A new synthesis of gougerotin (348) from methyl 4-azido-4-deoxy-D-gluco-pyranoside has been outlined. Analogues of gougerotin containing modifications to the sugar or the dipeptide or both have been described. Prumycin (349) has been synthesized from methyl 2-azido-2-deoxy-a-D-allo-pyranoside by the reactions shown in Scheme 119. 5 -0-Bromoacetyl- and 5 -o-chloroacetyl-puromycin have been prepared for use in the affinity labelling of ribosomal... 

Treatment of methyl 2-azido-4,6-0-benzylidene-2-deoxy-a-D-altro-pyranoside (128) (42) with 121 followed by refluxing and processing afforded a chloro derivative as a sirup in 70% yield (46, 49). Reduction of this product with an excess of Raney-nickel in methanol containing acetic anhydride afforded a crystalline product, m.p. 179°C., which is formulated as the d-manno analog 131. The actual product is most likely methyl azido-4,6-0-benzylidene-3-chloro-2,3-dideodxy - a - d - mannopyran-oside (130) resulting from attack of chloride ion at C-3 with inversion of configuration in the intermediate 129. Had the chlorination proceeded... 

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. " ... 

Methyl 2-deoxy-5-D-trityl-a-D-ery /iro-pentofuranoside, D-345 Methyl 2-deoxy-5-D-trityl-p-D-ery /iro-pentofuranoside, D-345 Methyl 2-deoxy-5- 0 -trityl-a-D-g/ycero -pentofuranosid-3-ulose, P-43 Methyl 2-deoxy-5- 0 -trityl- p-D-g/ycero -pentofuranosid-3-ulose, P-43 Methyl 4,6-di- 0 -acetyl-3-azido-2,3-dideoxy-a-D-ara6jMO -hexopyranoside, A-918... 

Treatment of the 2-triflate (224) of methyl 3-azido-4,6-0-benzylidene-3-deoxy-a-D-idopyranoside with BU4NF (DMF, r.t.) readily gave the... 

O-benzylidene-, benzyl ester N-(benzyloxycarbonyl)-, benzyl ester N-(benzyloxycarbonyl)-, methyl ester 2-azido-2-deoxy, N-(benzyloxycarbonyl)-benzyl ester methyl ester... 

Methyl 6-0-(3-0-Acetyl-2-Azido-4,6-0-Benzylidene-2-Deoxy-a- and 3-D-Galactopyrano-syl)-2,3,4-Tri-0-Benzyl-a-D-Galactopyranoside (110) A solution of xanthate 108 (1.2 mmol), glycosyl acceptor 11 (372 mg, 0.8 mmol) and activated 4-A powdered... 

Methyl 0-(2-Azido-3-0-Benzyl-4,6-0-Benzylidene-2-Deoxy-a-D-Galactopyranosyl)-(l-3)-0-(2-Azido-4,6-0-Benzylidene-2-Deoxy-(3-D-Galactopyranosyl)-(l-6)-2,3,4-Tri-O-Benzyl-a-D-Clucopyranoside (112) A mixture of the disaccharide acceptor 111 (0.1 mmol),... 

A fused OZT was obtained in the course of the reduction of vicinal azido-thiocarbonates via formation of the intermediate amine, which attacks the thiocarbonyl group (Scheme 37). The condensation reaction proved faster than the deoxygenation process for the synthesis of 2 -amino-2, 3 -dideoxyuridine50 or methyl 3-amino-4,6-0-benzylidene-3-deoxy-2-0-phenoxythiocarbonyl-a-L-talopyranoside.51... 

C14H24N4O7S 5-Azido-5-deoxy-l,2-0-isopropylidene-3-0-(methyl-sulfonyl)-/3-L-idofuranuronic N,N-diethylamide (AZDMIF10)91,92... 

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 reaction of methyl 2-azido-4,6-0-benzylidene-2-deoxy-a-D-altropyranoside (46) with 39 in refluxing 1,1,2,2-tetrachloroethane afforded a product which was formulated83(b) as methyl 2-azido-3,4-0-benzylidene-6-chloro-2,6-dideoxy-a-D-altropyranoside (47) the n.m.r. spectrum indicated that the product was a mixture of two diastereoisomers which differed in the configuration of the carbon atom of the benzylidene acetal. A possible mechanism for the formation of 47 is outlined. 

The conversion of 3-amino-3-deoxy sugars into pyrrolidines requires the presence of a leaving group, such as a p-tolylsulfonyloxy group on C-6 this is exemplified by the conversion of 3-azido-3-deoxy-l,2-0-isopropylidene-6-0-p-tolylsulfonyl-a-D-glucofuranose (44) and methyl 3-azido-2-benzamido-2,3-dideoxy-6-0-p-tolylsulfo-nyl-j8-D-glucopyranoside (46) into the respective pyrrolidines, 45 and 47, by reduction of the azido group, followed by cyclization.37... 

Piperidones of two types have been prepared from saccharide derivatives. Those of one type are lactams, exemplified by 187, obtained by oxidizing255 5-azido-5-deoxy-2,3-0-isopropyidene-/3-D-ribo-furanose (185) to 186, reducing the lactone 186 to the amine, and cyclizing this to 187. The other type comprises the 4-piperidones such as 189 this is obtained256 by oxidizing methyl a-D-arabinopyrano-side (188) with periodate, and treating the product with methylamine and 3-oxopentanedioic acid the bicyclic compound obtained from the a-glycoside differs from that from the /3 anomer. 

Nucleophilic displacement of the sulfonate groups in methyl 2,6,2, 3, 4 -penta-0-acetyl-3,6 -di-0-(methylsulfonyl)-/3-maltoside was readily achieved with sodium azide in hexamethylphosphoric triamide, to give methyl 3-azido-4-0-(6-azido-6-deoxy-a-D-gluco-pyranosyl)-3-deoxy-/3-D-allopyranoside pentaacetate.45 Catalytic hydrogenation of the 3,6 -diazide, followed by acetylation, gave the 3,6 -diacetamido derivative in high, overall yield. In a similar sequence of reactions, methyl 2,3,2, 3, 4 -penta-0-acetyl-6,6 -di-0-p-tolylsulfonyl-/3-maltoside has been transformed into the corresponding 6,6 -diac-etamido derivative.45... 

Comparison of the -n.m.r. spectrum of 3-0-(methylsulfonyl)-/3-maltose heptaacetate (31) with that of /3-maltose octaacetate showed only one divergence, —0.34 p.p.m. upfield of the H-3 resonance, indicative of the location of the methylsulfonyloxy group on C-3. A similar comparison of H-n.m.r.-spectral parameters as between methyl 4 -0-(methylsulfonyl)-/3-maltoside hexaacetate and methyl /3-maltoside heptaacetate revealed that the methylsulfonyloxy group in the former compound is located on C-4, as the H-4 resonance appeared —0.3 p.p.m. to higher field than the H-4 resonance for the heptaacetate.66 In the H-n.m.r. spectrum of methyl 3-azido-3-deoxy-/3-maltoside heptaacetate, the H-3 resonance appeared at 1.70 p.p.m. to higher field of... 

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