ISSN:
0170-2041
Keywords:
Galactosides, 3,4-pyruvylated
;
Oligosaccharides
;
Carbohydrates
;
Escherichia coli
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Treatment of phenyl 1-thio- and allyl 2,6-di-O-benzoyl-D-galactopyranosides 3 with methyl pyruvate and BF3 · Et2O in various solvents gave 1,6-anhydro-3,4-di-O-benzoyl-2-deoxy-2-phenylthio-β-D-idopyranose (4) and the corresponding diastereomers of 3,4-O-pyruvate acetal-containing galactosides 5. The phenyl 1-thio-β-galactoside R-5a and the allyl a-galactoside R-5b were both converted into methyl 3,4-O-[1-(R)-(methoxycarbonyl)ethylidene]-β-D-galactopyranoside (9), the structure of which as well as that of 4 was confirmed by X-ray crystallography. Compound R-5a was converted into 5-[(benzyloxycarbonyl)amino]pentyl 6-O-benzoyl-3,4-O-[1-(R)-(methoxycarbonyl)ethylidene]-β-D-galactopyranoside (18) by using the (2-chloroacetoxymethyl)benzoyl (CAMB) group for the temporary protection of position 2. Glucosamination of 18 and subsequent deblocking of the intermediate disaccharide gave β-D-GlcpNAc-(1→2)-3,4-(S)-pyruvate-β-D-Galp-O(CH2)5NH2 (21) which represents a fragment of the Escherichia coli K 47 polysaccharide.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199419940903
