Synthesis and Polycondensation of Galacto-Configurated Monomers Via the Trityl-cyano-ethylidene-Procedure
Titel:
Synthesis and Polycondensation of Galacto-Configurated Monomers Via the Trityl-cyano-ethylidene-Procedure
Auteur:
Vogel, Christian Bergemann, Claudia Boye, Hanna Ott, A. Ya. Betaneli, V. I. Kochetkov, N. K.
Verschenen in:
Journal of carbohydrate chemistry
Paginering:
Jaargang 13 (1994) nr. 1 pagina's 47-62
Jaar:
1994-01-01
Inhoud:
4-O-Acetyl-1,2-[1-(exo-cyano)ethylidene]-3-O-trityl-α-d-fucopyranose (13) and methyl 4-O-acetyl-1,2-O-[1-(exo-cyano)ethylidene]-3-O-trityl-α-d-galactopyranuronate (14) were synthesised. Trityl-cyanoethylidene condensation of the monomer 14 gave protected β-d-GalpA-(1→3)-d-GalpA-oligosaccharide derivatives with high stereoselectivity and a degree of polymerisation (d.p.) of eight. In the case of the d-fucose monomer 13, the yield of oligomers is surprisingly low and the d.p. does not exceed seven. This result is in contrast to the d.p. 20-60 obtained with other 6-deoxy-sugars, as previously described by Kochetkov and coworkers.