Chlorosulphation of amino sugars: synthesis of methyl 2-acetamido-4-amino-2,4,6-trideoxy-β-D-glucopyranoside (bacillosamine) from a D-glucosamine derivative

Abstract

This paper is dedicated to Prof. Raymond U . Lemieux on the occasion of his 60th birthday DAVID R. BUNDLE and STAFFAN JOSEPHSON. Can. J. Chem. 58,2679 (1980). Chlorosulphation of methyl 2-deoxy-2-phthalimido-P-D-glucopyranoside 3 under controlled conditions provided either methyl 6-chloro-2,6-dideoxy-2-phthalimido-~~-glucopyranoside 4 or methyl 4,6dichloro-2,4,6trideoxy-2-phthalimido-~-~-galactopyranoside 5. Chlorination at C-4 occurs to the exclusion of that at C-3, in sharp contrast to the chlorosulphation of methyl P-D-glucopyranoside which is known to give both the 4,6-dichloro-galacto-and 3,6dichloro-allo-pyranosides. Conversion of the chlorinated phthalimido derivatives 4and 5 to the corresponding 2-acetamido-2-deoxyhexopyranosides 6 and 7 permitted reduction of the chloro functions by palladium, W-4 m n e y nickel, and nickel boride. Reduction of methyl 2-acetamido-6-chloro-2,6-dideoxy-P-D-glucopyranoside 6 by Raney nickel gave methyl 2-acetamido-2,6-dideoxy-P-D-glucopyranoside 8. Selective dechlorination at C-4 was achieved by palladium catalysed reduction of methyl 2-acetamido-4,6-dichloro-2,4,6-trideoxy-~-~-galactopyranoside 7. Nickel boride or Raney nickel reduction of 7 effected selective dechlorination at C-6 to give methyl 2-acetamido-4-chloro-2,4,6-trideoxy-P-D-galactopyranoside 9. Azide displacement of the 4-chloro group of 9 provided a simple route to the 2,4-diamino sugar bacillosamine. A side product of the azide displacement reaction was the unsaturated sugar, methyl 2-acetamido-2,4,6trideoxy-a-L-threo-hex-4-enopyranoside, 14.

Recent advances in synthesis of bacterial rare sugar building blocks and their applications

“…C-4 inversion of D-fucosamine with an amine source gives access to Bac. Accordingly, transformation of D-glucosamine, 30,31 D-galactosamine 32 and D-fucal 33 to the corresponding D-fucosamine derivatives as described above, and subsequent nucleophilic displacement of their C-4 chloride, mesylate, tosylate or triate derivatives with azide nucleophile afforded the D-bacillosamine derivatives (Fig. 4, paths A, B and C).…”

Strategies for the synthesis of branched oligosaccharides of the Shigella flexneri 5a, 5b, and variant X serogroups employing a multifunctional rhamnose precursor

“…Back extraction of the aqueous phase with ether, followed by concentration of the ether extracts gave a mixture that was separated by silica gel column chromatography with ethyl acetate-hexane [2: 1 (v/v)] as the eluant. The de-allylated disaccharide (18) (870 mg, 72%) crystallized (from ethyl acetatehexane), m.p. 147-147.5 "C Cali4 -25.9" (c 0.5, in dichloromethane) (Found: C, 56.2; H, 6.55; N, 2.45.…”

“…solution of glucosyl bromide (13), prepared from tetra-0-benzylglucose (362 mg, 0.67 mmol) dissolved in dichloromethane (320 cm3) was added dropwise to a stirred solution of the disaccharide (18) (200 mg, 0.335 mmol) in dichloromethane (5 cm3) containing 4A molecular sieves and mercury(r1) bromide (144 mg, 0.4 mmol). Further mercury(I1) bromide (140 mg) and molecular sieves were added after 18 h and the reaction allowed to proceed for a further 4 h. The reaction mixture was worked up and chromatographed in the manner described for compound (20) N, 1.25%); 6, (CDClJ, 103.5 (C-l"P), 102.9 (C-1'), 99.9 (C-1),…”

Concise and Efficient Synthesis of 2-Acetamido-2-deoxy-β-d-hexopyranosides of Diverse Aminosugars from 2-Acetamido-2-deoxy-β-d-glucose

“…Conversion of d -GlcNAc to other 2-amino-2-dexoyhexoses is thus an attractive and economically viable strategy. However, most of the reported routes require either tedious transformation or harsh conditions. − The development of concise syntheses of unusual aminosugars is therefore of practical interest. Here, we extend our recent report of a facile and efficient two-step synthesis of 2-acetamido-2-deoxy-β- d -glucopyranosides from commercial d -GlcNAc via the 5,6- O -isopropylidene furanose derivative 1 to the synthesis of the aminosugars ( 2 − 7 ) (Figure ).…”