Carbohydrates Containing Nitrogen in a Five-Membered Ring and an Attempted Synthesis of a Carbohydrate With Nitrogen in a Seven-Membered Ring

Abstract

Lead tetraacetate oxidation of 6-acetamido-6-deoxy-D-galactose ( I S ) yielded a syrup which was converted to a compound formulated as 4-acetamido-4-deoxy-l,2-0-i~o~ropylidene-Dthreofuranose (XII). The same syrup was obtained by alkaline degradation of the product of oxidation of 5-acetamido-5-deoxy-D-xylose diethyl dithioacetal (XVII) with peroxypropionic acid. Treatment of compound XI1 with p-toluenesulfonyl chloride yielded crystalline 4-acetamido-4-deoxy-1,2-0-isopropylidene-3--p-tolysufo1yl-~-threofuranose (XIII).Dernercaptalation of 6-acetamido-2,3,4,5-tetra-0-acetyl-6-deoy-~-gaactose diethyl dithioacetal (SS) with mercuric chloride and cadmium carbonate ~n aqueous acetone did not yield a nitrogen-containing septanose ring but an acyclic derivative. CARBOHYDRATES CONTAINIXG NITROGEZV IN A FIVE-MEMBERED R I N GIn a previous paper (I) froin this laboratory the synthesis of methyl 4-acetamido-4-deoxy-L-erythrofuranoside (I), the first example of a sugar with nitrogen in a fiveinenlbered ring, was described. Very shortly after this announcement, Hanessian and Haslcell (2) reported that they had obtained syrupy 4-acetamido-4-deoxy-L-erythrofuranose by the alkaline degradation of 5-acetamido-5-deoxy-L-arabinose diethylsulfonal. In the same paper Hanessian and Hasltell reported the preparation of a novel sugar derivative, 4-amino-4-deoxy-D-erythronolactain (11). In the present publication we describe the synthesis by two different routes of derivatives of 4-acetamido-4-deoxy-Dthreofuranose (XI). 1,2;3,4-Di-0-isopropylidene-a-~-ga1actopyran0se (IV) (3) was prepared from D-galactose (111) and treated with p-toluenesuIfony1 chloride in pyridine to give 1,2;3,4-di-O-isopropylidene-6-0-p-to~ylsulfonyl-a-~-galactop~ranose (V) (4). Con~pound V reacted with sodium azide in N,N-dimethylformamide t o afford a homogeneous pale yellow oil, the infrared spectrunl of which showed the highly characteristic azide group absorption a t 2 100 cm-I but no aromatic ring and sulfonate group absorptions. The new substance is therefore G-azido-G-deoxy-1,2;3,4-di-0-isopropylidene-a-~-galactopyranose (VI). This derivative could be reduced to 6-ai1~ino-6-deoxy-1,2;3,4-di-O-isoprop~~lidene-a-~-galactopyranose (VII) ( 5 ) by merely stirring it with a n excess of Raney nickel, a procedure described by Wolfrom et al. (6). Treatment of compound VII with acetic anhydride in pyridine afforded a glass which gave a negative ninhydrin reaction. The glassy product 'Preset~ted i n part at the Intertzational Synzposiunz on Carbohydrate Clzeftzistry, Miinster, July 13-17,1964. 2Present address:

Synthesis, Crystal Structure, Electronic Spectroscopy, Electrochemistry and Biological Studies of Ferrocene–Carbohydrate Conjugates

“…The carbohydrate derived azido substrates for the intermolecular 1,3‐dipolar cycloaddition was prepared by an S N 2 displacement reaction of the corresponding tosylate or mesylates with sodium azide in DMF at reflux temperatures 42,53,54. The corresponding triazoles 4a – e were prepared by click reaction55 between sugar azides 3a – e and ferrocenylacetylene in the presence of copper(II) sulfate and sodium ascorbate in a 1:1 mixture of t BuOH/H 2 O (Scheme ), in good yield.…”

“…Ferrocenecarbaldehyde was purchased from Aldrich Co. and ferrocenylacetylene was prepared according to a literature procedure 70. All the azido sugars were prepared according to literature procedures 41,43,53,54…”

“…[42,53,54] The corresponding triazoles 4a-e were prepared by click reaction [55] between sugar azides 3a-e and ferrocenylacetylene in the presence of copper(II) sulfate and sodium ascorbate in a 1:1 mixture of tBuOH/H 2 O (Scheme 2), in good yield. [42,53,54] The corresponding triazoles 4a-e were prepared by click reaction [55] between sugar azides 3a-e and ferrocenylacetylene in the presence of copper(II) sulfate and sodium ascorbate in a 1:1 mixture of tBuOH/H 2 O (Scheme 2), in good yield.…”

Helical Self‐Assembly of Optically Active Glycoconjugated Phthalocyanine J‐Aggregates

“…[36] Subsequently, the free hydroxyl group at position 6 was tosylated (77 % yield) followed by nucleophilic substitution of the tosylate by azide to afford 6 in 96 % yield (see Supporting Information). [37] Both glycoconjugated phthalonitriles 9 and 10 were prepared by copper catalysed alkyneazide cycloaddition (CuAAC or "Click" reaction) in THF as the solvent with copper(I)iodide as catalyst and N,N,N',N'',N''pentamethyldiethylenetriamine (PMDTA) as base (Scheme 1). [33d,38] The isomeric bis ethynyl phthalonitriles 7 and 8 were prepared according to literature procedures.…”

Synthesis and Applications of Carbohydrate-Based Organocatalysts

“…The tetra- O -acetyl-β- d -glucopyranosyl azide was prepared from the d -glucose via acetylation, bromination of anomeric position (as described above for the synthesis of isothiocyanates) and reaction with sodium azide at room temperature in DMF (81%) [ 64 ]. The 6-azido-6-deoxy-1,2:3,4-di- O -isopropylidene-α- d -galactopyranose, precursor of the urea 127 , was easily obtained from the corresponding 6-hydroxyl derivative by tosylation and nucleophilic substitution with sodium azide [ 65 ]. Finally, the 1,2- trans configured disaccharidic azides were prepared with a 75–85% yield by treating the corresponding β- d -octaacetates with trimethylsilyl azide in the presence of SnCl 4 [ 66 ].…”