Virginia Daoust

The specific capsular polysaccharide of Streptococcus pneumoniae type 15F

The specific capsular polysaccharide produced by Streptococcus pneumoniae type 15F (American type 15) is composed of D-galactose (3 parts), D-glucose (1 part), 2-acetamido-2-deoxy-D-glucose (1 part), phosphate (1 part) and O-acetyl (2 parts). Methylation, periodate oxidation, nitrous acid deamination, optimal rotation and nuclear magnetic resonance studies showed that the polysaccharide is a high mol. wt linear polymer of a pentasaccharide repeating unit having the structure.

A Synthesis of 2-amino-2,6-dideoxy-L-mannose (L-rhamnosamine) and 2-amino-2,6-dideoxy-L-glucose (L-quinovosamine),

Abstract : The note records the successful synthesis of 2-amino-2,6-dideoxy-L-mannose(L-rhamnosamine) and 2-amino-2,6-dideoxy-L-glucose(L-quinovosamine) from 5-deoxy-L-arabinose by the nitromethane addition-method.

A Synthesis of 2-Acetamido-2,6-dideoxy-D-glucose, 2-Acetamido-2, 6-dideoxy-D-idose, and 2,6-Dideoxy-D-xylo-hexose (Boivinose),

The base-catalyzed addition of nitromethane to 5-deoxy-D-xylose gave a mixture of 1,6-dideoxy-1-nitro-D -gulitol (2) and 1,6-dideoxy-1-nitro-D-iditol (3) (ca. 1;1) which underwent the Nef reaction to give 6-deoxy-D-gulose and 6-deoxy-D-idose, Acetylation of mixed 2 and 3 afforded the corresponding 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1-nitro-D-gulitol (4) and 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1-nitro-D-iditol (5) derivatives which on treatment with methanolic ammonia yielded 2-acetamido-1,2,6-trideoxy-1-nitro-D-gulitol (11) and 2-acetamido-1,2,6-trideoxy-1-nitro-D-iditol (12) (ca. 6:1). Compounds 11 and 12 underwent the modified Nef reaction to give 2-acetamido-2,6-dideoxy-D-gulose (13) and 2-acetamido-2,6-dideoxy-D-idose (14) which were separated by cellulose column chromatography.Compound 4 was converted to 3,4,5-tri-O-acetyl-1,2,6-trideoxy-1-nitro-D-xylo-hex-1-enitol (6) which on catalytic reduction gave 3,4,5-tri-O-acetyl-1,2,6-trideoxy-1-nitro-D-xylo-hexitol (7). Compound 7 underwent the Nef reaction ...

A Synthesis of 2-Acetamido-2,6-Dideoxy-D-Allose and 2-Acetamido-2,6-Dideoxy-D-Altrose,

Abstract : 2-Acetamido-2,6-dideoxy-D-allose and 2-acetamido-2,6-dideoxy-D-altrose were prepared from 5-deoxy-D-ribose via a synthetic sequence including modified Nef reactions.