ISSN:
1434-4475
Keywords:
Deoxygenation of sialic acids
;
Xanthogenates of sialic acids
;
Reaction of side chain deoxy-iodo sialic acids with tributyltinhydride
;
Reaction of xanthogenates of sialic acids derivatives with tributyltinhydride
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The 7- and 8-Iodnonulosonic acid derivatives1 and2 react with tributyltinhydride-AIBN to the 7- and 8-deoxy-N-acetylneuraminic acid derivatives3 a and4 a which after hydrolysis give the 7-deoxy-N-acetylneuraminic acid3 b (5-N-acetamido-3,5,7-trideoxy-β-D-galacto-2-nonulopyranosidonic acid=7-Deoxy-Neu5Ac) and 8-deoxy-N-acetylneuraminic acid4 b (5-N-acetamido-3,5,8-trideoxy-β-D-galacto-2-nonulopyranosidonic acid=8-Deoxy-Neu5Ac). The 4,8,9-tris-(t-butyldimethylsilyl)-N-acetylneuraminic acid derivative5 a yields after transformation to the 7-O-acetyl compound5 b and partial removing of the protecting groups the derivative5 c. Further reaction with theMitsunobu-reagent and methyliodide affords the 9-Iodocompound6 a which turned to the 8-O-acetylderivative6 b. Subsequent reduction by means of tributyltinhydride yields first the 9-deoxyderivative7 a and after hydrolysis the 9-deoxy-N-acetylneuraminic acid7 b (5-N-acetyl amido-3,5,9-trideoxy-D-glycero-β-d-galacto-2-nonulopy-ranosidonic acid=9-Deoxy-Neu5Ac). Another synthesis of7 b follows the route8 f →8 g →7 c. The Deoxy-N-acetylneuraminic acid3 b could be prepared also by an alternative procedure using the methyl-β-8,9-methylethylen-4-O-t-butyldimethylsilyl-N-acetylneuraminic acid methylester8 a via the intermediate compounds8 d and8 e. Application of the 8,9-O-methylethyliden-N-acetylneuraminic acid derivative8 opens an approach to the xanthogenates8 a and8 b which could be reduced to the deoxy-N-acetylneuraminic acid derivatives9 a and10 a. Hydrolysis of10 a yields the 4,7-dideoxy-N-acetylneuraminic acid10 b (5-N-acetamido-3,4,5,7-tetradeoxy-β-D-lyxo-2-nonulopyranosidonic acid=4,7-Dideoxy-Neu5Ac).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00810094
Permalink
