ISSN:
0947-3440
Schlagwort(e):
Wittig reactions
;
Amphiphiles
;
L-Fucose analogues
;
Nucleotides
;
Fucosyltransferase
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Starting from the 6-O-tert-butyldimethysilyl-2,3;4,5-di-O-isopropylidene-D-galactose diethyl dithioacetal (4) and proceeding through a Wittig reaction and Swern oxidation, a series of L-fucose analogues, which unlike the normal L-fucose possess an extended alkyl-chain at C-5, can be produced. The elongated carbon backbone in the L-fucitols (22-25) as well as in the L-fucose derivatives (30-33) increases the hydrophobic nature of the sugar molecule, promoting liquid-crystalline properties in both series. The further derivatization of the L-fucose analogues 30, 31 leads to the corresponding β-L-galacto-deco- and dodeco-pyranosyl phosphates 46, 47 and, in turn, to the respective pyranosyl guanosine 5-diphosphates 48, 49. The reaction of the β-L-galactopyranosyl guanosine 5-diphosphate 48 with 8-methoxycarbonyloctyl 2-acetamido-2-deoxy-4-O-(β-D-galactopyranosyl)-β-D-glucopyranoside (50) in the presence of a 3/4-α-fucosyltransferase furnished an O-glycosidic linkage of the α-L-galactopdecopyranose 30 at the 3-O-position of the N-acetyllactosamine glycoside 50. The chemo-enzymatic coupling reaction proves that the synthesized carbon-backbone-elongated L-galactopyranosyl guanosine 5-diphosphates are suitable substrates for the α-fucosyltransferases.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.199719970323
