C. Vogel et al., SYNTHESIS AND POLYCONDENSATION OF GALACTO-CONFIGURATED MONOMERS VIA THE TRITYL-CYANOETHYLIDENE-PROCEDURE, Journal of carbohydrate chemistry, 13(1), 1994, pp. 47-62
-cyano)ethylidene]-3-O-trityl-alpha-D-fucopyranose (13) and methyl eth
ylidene]-3-O-trityl-alpha-D-galactopyranuronate (14) were synthesised.
Trityl-cyanoethylidene condensation of the monomer 14 gave protected
beta-D-GalpA-(1-->3)-D-GalpA-oligosaccharide derivatives with high ste
reoselectivity and a degree of polymerisation (d.p.) of eight. In the
case of the D-fucose monomer 13, the yield of oligomers is surprisingl
y low and the d.p. does not exceed seven. This result is in contrast t
o the d.p. 20 - 60 obtained with other 6-deoxy-sugars, as previously d
escribed by Kochetkov and coworkers.