259534-65-1

Upstream product

• 154461-26-4 methyl 4,6-O-benzylidene-α-L-glucopyranoside 
• 189188-36-1 (2R,3R,4R,5R,6R)-5-Azido-4-benzyloxy-3-hydroxy-6-methoxy-tetrahydro-pyran-2-carboxylic acid methyl ester 

Downstream Products

• 259534-66-2 (2R,3R,4R,5R,6R)-4-Benzyloxy-3-hydroxy-6-methoxy-5-(2,2,2-trichloro-acetylamino)-tetrahydro-pyran-2-carboxylic acid methyl ester 
• 259534-71-9 (2R,3R,4R,5R,6R)-5-Acetylamino-3-((2S,3R,4R,5R,6R)-3-acetylamino-5-azido-4-hydroxy-6-methyl-tetrahydro-pyran-2-yloxy)-4-benzyloxy-6-methoxy-tetrahydro-pyran-2-carboxylic acid 
• 259534-70-8 (2R,3R,4R,5R,6R)-3-[(2S,3R,4R,5S,6R)-4-Acetoxy-5-azido-6-methyl-3-(2,2,2-trichloro-acetylamino)-tetrahydro-pyran-2-yloxy]-4-benzyloxy-6-methoxy-5-(2,2,2-trichloro-acetylamino)-tetrahydro-pyran-2-carboxylic acid methyl ester 

Relevant academic research and scientific papers

Synthesis of the repeating unit of the O-specific polysaccharide of Shigella sonnei and quantitation of its serologic activity

The chemical synthesis of the zwitterionic disaccharide 2 is described that corresponds to the repeating unit of the O-specific polysaccharide (1) of the Gram-negative human pathogen Shigella sonnei. Passive hemolysis inhibition tests using a hyperimmune

Synthesis of the monosaccharide units of the O-specific polysaccharide of Shigella sonnei

The monosaccharide components of the O-specific polysaccharide 1 of the lipopolysaccharide of the enteropathogenic bacterium Shigella sonnei were synthesized as their methyl glycosides 2 and 3 in their natural anomeric form. The key intermediate to the diaminotrideoxygalactose derivative 2 was ethyl-3-O-acetyl-2-deoxy-2-phthalimido-1-thio-β-D- glucopyranoside (9) that was converted to its ditosylate 10. Regioselective deoxygenation at C-6 followed by nucleophilic displacement of the secondary tosyloxy group by azide afforded the 4-azido thioglycoside 13. Methyl trifluoromethanesulfonate-assisted methanolysis of 13 gave the O-glycoside 14. Replacement of the phthalimido by an acetamido group followed by catalytic reduction of the azido group led to the diamino-trideoxygalactose derivative 2. The precursor to the L-altruronic acid derivative 3 was methyl α-L-glucopyranoside (19) that was routinely converted to the benzylidene-protected 2,3-anhydro-allopyranoside 22. Regioselective opening of the epoxide ring by NaN3 afforded the 2-azido derivative 23 that was benzylated at HO-3. Hydrolytic removal of the benzylidene group followed by TEMPO oxidation of C-6 and subsequent esterification with MeI gave the key L-azido-altruronic acid intermediate 29 that was transformed to the acetamido-altruronic acid derivative 3. High resolution NMR data of the altruronic acid derivatives indicate that the conformation of their pyranose ring is crucially dependent on the substitution pattern: the 2-azido altruronic acid derivatives prefer the 4C1 conformation whereas the 2-acetamido congeners exist preferentially in the 1C4 conformation.